Polaris ProXP

AR8690 - Polaris XP Turbo (16-up) / XP 1000 (14-up) ARP2000 Head Stud Kit

Made from ARP2000 material and rated to 220,000 psi, ARP cylinder head studs not only offer super...

Made from ARP2000 material and rated to 220,000 psi, ARP cylinder head studs not only offer superior clamp loads over cylinder head bolts, they provide proper alignment of the head and gasket with more accurate and consistent torque loading. Bolts will actually twist while torquing to proper spec, greatly reducing their ability to hold true.

BC9004 - ARP Polaris RZR XP Wheel Stud Kit - New Design (set/4)

Exclusive @arpbolts SxS wheel studs deliver the strength and performance required for extreme of...

Exclusive @arpbolts SxS wheel studs deliver the strength and performance required for extreme off-road use, whether it’s the dunes, trails, rocks or the race track. Made from heat-treated 8740 chromoly with cadmium plating for added corrosion resistance, ARP studs deliver 200,000psi tensile strength vs 150,000psi on the factory Grade 8 studs. ARP studs are designed with added shoulder length for proper wheel engagement, an oversize splined grip that keeps the stud secure on the hub and a pro...

BC9990 - SxS Valve Spring Compressor/Installation Tool

The BC valve spring compressor and installation tool for the Polaris RZR, Can-Am X3 and Yamaha YX...

The BC valve spring compressor and installation tool for the Polaris RZR, Can-Am X3 and Yamaha YXZ allows quick and easy assembly of a complete SxS cylinder head in minitues. Even works while the head is installed on the engine in the car using compressed air through the spark plug hole. Install valve springs, retainers, valves and keepers fast and efficiently. Includes the following: Base housing that threads into spark plug hole. Pivoting arm to install 4 valves per hole.    3 spring/retai...

BC9002-12 - ARP Polaris RZR XP1000, Xp Turbo, XP Turbo-S Rear Trailing Arm, Hub & 12mm Rad...

Exclusive ARP rear trailing arm, hub and radius rod (12mm) kit bolt kit for the Polaris RZR. Fea...

Exclusive ARP rear trailing arm, hub and radius rod (12mm) kit bolt kit for the Polaris RZR. Features 12pt, polished stainless steel bolts rated to 180,000psi, far superior to the Grade 8 stock bolts and a way better look. Fits Polaris RZR XP1000 and XP Turbo (16-up)

BC9001-S - ARP Polaris RZR XP Turbo-S Front A-Arm Suspension & Hub Fastener Kit

BC x ARP exclusive front A-Arm suspension, spindle and hub bolt kit for the Polaris RZR. Features...

BC x ARP exclusive front A-Arm suspension, spindle and hub bolt kit for the Polaris RZR. Features 12pt, polished stainless steel bolts rated to 180,000psi, far superior to the Grade 8 stock bolts and a way better look. Fits Polaris RZR XP Turbo-S (18-up)

BC3991 - Polaris XP Turbo (16-up) / XP 1000 (14-up) Valve Stem Seat/Seals Designed for Sto...

BC valve stem seals are designed for OEM Polaris (stock) top hat style seat. Integrated seat/seal...

BC valve stem seals are designed for OEM Polaris (stock) top hat style seat. Integrated seat/seal for OEM valve guides when using stock or BC spring/retainer if running stock cams or cams under.430" lift. The seals allow a carefully defined amount of engine oil from the cylinder head into the combustion chamber—to lubricate the rotating valve stem in the valve guide. BC valve stem seals are produced from high performance materials for increased part life and lower wear.

BC8290-1 - Polaris XP Turbo / XP 1000 (93/94mm x .028”) Cometic MLX Head Gasket

MLX design for non O-ringed cylinder jug fits 93mm or 94mm bore, .028” Thickness - Cometic three ...

MLX design for non O-ringed cylinder jug fits 93mm or 94mm bore, .028” Thickness - Cometic three layer gaskets combine advanced materials with state-of-the-art manufacturing processes to provide custom-tailored solutions to meet the needs of each individual application. The MLX head gasket is comprised of a three layer setup - Viton coated embossed spring steel outer layers surround a steel inner layer that provides support and thickness to the gasket. Embossments on the gasket allow for a pr...

AR8691 - Polaris XP Turbo (16-up) / XP 1000 (14-up) ARP CustomAge625+ Head Stud Kit

Made from ARP625+ Custom Age material and rated to 280,000 psi, ARP cylinder head studs not only ...

Made from ARP625+ Custom Age material and rated to 280,000 psi, ARP cylinder head studs not only offer superior clamp loads over cylinder head bolts, they provide proper alignment of the head and gasket with more accurate and consistent torque loading. Bolts will actually twist while torquing to proper spec, greatly reducing their ability to hold true.

BC8880 - Polaris XP Turbo (16-up) / XP 1000 (14-up) Cam Bucket Followers

Shimless bucket design, uses shim in retainer. Made from aerospace grade, 4140 chromoly steel all...

Shimless bucket design, uses shim in retainer. Made from aerospace grade, 4140 chromoly steel alloy and completely CNC machined from heat-treated billet round bar. Heavy-duty wall thickness eliminates distortion and cam face depression, while reducing overall weight from non-critical stress areas. Nitrided and polished to a surface hardness of 60RC for minimal wear. Provides lower friction with cam lobes and cylinder head lifter bores for improved durability.

BC8878 - NEW Polaris Adjustable Cam Gears - Int/Exh (pair) for XPTurbo, XP1000, XP900, 570

Machined from hardened steel alloy and fully compatible with the stock Polaris timing chain (BC h...

Machined from hardened steel alloy and fully compatible with the stock Polaris timing chain (BC has new Cloyes timing chains also), the BC adjustable cam gears for the Polaris RZR platform are the perfect way to gain top end or low end torque depending on how you dial in the gear settings. Separate intake and exhaust gears to avoid confusion, these gears allow for 5 degrees of advance or retard for both intake and exhaust cams with easy to read indicator marks. If running with BC cams, which ...

BC0900 - Polaris XP Turbo (16-up) / XP 1000 (14-up) Beehive Spring/Titanium Retainer/Seat Kit

Designed for high rpm, BC valve springs by PAC Racing are wound from only the highest grade, supe...

Designed for high rpm, BC valve springs by PAC Racing are wound from only the highest grade, super clean, chrome silicone alloy and feature proprietary processing procedures for consistent pressures. BC retainers are machined from premium 6AL4V titanium alloy for added valve control above 10,000 rpm. Also requires BC3991 valve stem seals. Type BC1900 Single Free Length 1.610" Seat 1.265" @ 83 lbs Open 0.850" @ 197 lbs Coil Bind 0.760" Retainer BC2901 Spring Seat BC2911 Net Ca...

BC3802 - Polaris XP Turbo (16-up) / XP 1000 (14-up) Stainless Steel Intake Valves - 38.8mm...

BC valves are one piece design with a friction welded Stellite tip for the best possible performa...

BC valves are one piece design with a friction welded Stellite tip for the best possible performance. Every valve is made from premium grade, heat resistant stainless steel material to insure reliability with high boost and/or high rpm applications. The undercut stem above the head area not only reduces overall weight for extended rpm potential, but also significantly improves air/fuel flow in and out of the combustion chamber. Every valve is fully machined and features a swirl polished finis...

BME9051 - Polaris XP Turbo (16-up) BME Shelf Pistons w/All Hardware - 93mm x 9.5:1

Stock bore (93mm) in 9.5:1 compression, BME pistons for the stock stroke (68mm) RZR XPTurbo are ...

Stock bore (93mm) in 9.5:1 compression, BME pistons for the stock stroke (68mm) RZR XPTurbo are made exclusively for BC and include the following features: • Made from 2816-T61 aluminum forgings. • Full round design, notched for squirters.• Pocketed skirts for added support/rigidity.• Valve reliefs for safety margin if broken belt. • 8620 tool steel material pins in .190” wall. • Total Seal rings, 1.2mm top ring, big radial wall.• Use with BC6911 or BC6912 rods. While BME's flagship piston p...

TUR001 - TurboSmart Internal Wastegate for Polaris ProXP/Turbo R Turbochargers

Turbosmart Upgraded Wastegate Actuators for the Polaris ProXP and Turbo R come preset to 5psi cra...

Turbosmart Upgraded Wastegate Actuators for the Polaris ProXP and Turbo R come preset to 5psi crack pressure and have been developed to provide maximum possible boost response for your factory frame turbocharger. The Turbosmart IWG75 Series of upgraded Actuators benefit from an increased ‘Working Ratio’ over the factory equipment resulting in improved boost response, throughout the RPM range. This Improved ‘working ratio’ is achieved through an increase to the effective surface area of the di...

BC3890 - Polaris XP Turbo (16-up) / XP 1000 (14-up) Valve Lash Adjusters

BC valve lash adjusters are CNC machined from S7 tool steel for the ultimate in wear resistance. ...

BC valve lash adjusters are CNC machined from S7 tool steel for the ultimate in wear resistance. Each shim kit includes 36 pieces from in twelve varying thicknesses starting at 2.3mm thick all the way up to 2.85mm thick in 0.05mm increments. 3 shims in each thickness.

BC4910C - Customer supplied Polaris XPTurbo Crankcase w/Linebore, Shuffle Pin, ARP main st...

CUSTOMER SUPPLIED CRANKCASE - This is the hot setup for any Polaris RZR build (XPT and XP1000), ...

CUSTOMER SUPPLIED CRANKCASE - This is the hot setup for any Polaris RZR build (XPT and XP1000), especially big horsepower (over 250whp), endurance racing or anyone who's had rod or crank failure and are searching for more reliability out of their RZR engine.  You supply the crankcase (new cases available upon request for $1200) for lineboring, shuffle pinning, King main bearings and ARP2000 main studs. See leadtimes below for machining time frames from each shop (note: these times may vary d...

AR8790 - Polaris XP Turbo (16-up) / XP 1000 (14-up) ARP Case Stud Kit

***NOTE: Must have linebored main journals and oversize King main bearings (BC4900) to use these ...

***NOTE: Must have linebored main journals and oversize King main bearings (BC4900) to use these case studs otherwise housing bore distortion will occur and crankshaft will not rotate.*** If using on a stock RZR crankcase, recommend AR8791 case bolts. Made from ARP2000 material and rated to 220,000 psi, ARP case stud kits not only offer superior clamp loads over stock, torque to yield case bolts, they provide proper alignment of the both case halves with more accurate and consistent torque lo...

BC3990 - Polaris XP Turbo (16-up) / XP 1000 (14-up) Valve Stem Seals Designed for BC3965/A...

BC valve stem seals are designed for standard aftermarket valve guides like BC3965. The seals all...

BC valve stem seals are designed for standard aftermarket valve guides like BC3965. The seals allow a carefully defined amount of engine oil from the cylinder head into the combustion chamber—to lubricate the rotating valve stem in the valve guide. BC valve stem seals are produced from high performance materials for increased part life and lower wear.

BC3801 - Polaris XP Turbo (16-up) / XP 1000 (14-up) Stainless Steel Exhaust Valves - 29.2m...

BC valves are one piece design with a friction welded Stellite tip for the best possible performa...

BC valves are one piece design with a friction welded Stellite tip for the best possible performance. Every valve is made from premium grade, heat resistant stainless steel material to insure reliability with high boost and/or high rpm applications. The undercut stem above the head area not only reduces overall weight for extended rpm potential, but also significantly improves air/fuel flow in and out of the combustion chamber. Every valve is fully machined and features a swirl polished finis...

BC9911 - NEW Polaris XP Turbo CNC Cylinder Head - Big Port 38.8mm/33mm Valves

Use pulldowns above to build out your head. The BC core exchange program works three ways: 1) Buy...

Use pulldowns above to build out your head. The BC core exchange program works three ways: 1) Buy one of BC's new heads outright, no exchange. 2) Send a new head in for even exchange for one of BC's new "in-stock" heads. 3) Send a used head in, receive that same head back. BC only accepts new, never-been ran Polaris XPTurbo (#3023773) or XP1000 (#3022716) cylinder heads as new core exchanges as they are virtually the same. BC uses only new XPT, or XP1000 for all new even exchanges. All heads ...

BC9002-10 - ARP Polaris RZR XP1000, Xp Turbo, XP Turbo-S Rear Trailing Arm, Hub & 10mm Rad...

Exclusive ARP rear trailing arm, hub and radius rod (10mm) kit bolt kit for the Polaris RZR. Feat...

Exclusive ARP rear trailing arm, hub and radius rod (10mm) kit bolt kit for the Polaris RZR. Features 12pt, polished stainless steel bolts rated to 180,000psi, far superior to the Grade 8 stock bolts and a way better look. Fits Polaris RZR XP1000 and XP Turbo (16-up)

BME9060 - Polaris Pro R 2.0L (21-up) BME Shelf Pistons w/All Hardware - 93mm x 9.5:1

Stock bore (93mm) in 9.5:1 compression, BME pistons for the stock stroke (73.5mm) Polaris Pro R ...

Stock bore (93mm) in 9.5:1 compression, BME pistons for the stock stroke (73.5mm) Polaris Pro R are made exclusively for BC and include the following features: • Made from 2816-T61 aluminum forgings. • Full round design, notched for squirters.• Pocketed skirts for added support/rigidity.• Valve reliefs for safety margin if broken belt. • 8620 tool steel material pins in .190” wall. • Total Seal rings, 1.2mm top ring, big radial wall.• Use with BC6915 or BC6916 rods. While BME's flagship pist...

BC3966 - Polaris XP Turbo / XP 1000 Valve Guides

5.5mm Stem Diameter fits both Intake and Exhaust - BC premium valve guides feature a threaded end...

5.5mm Stem Diameter fits both Intake and Exhaust - BC premium valve guides feature a threaded end where the valve stem seal goes, virtually eliminating the seal popping off at extended rpm's. Made from Manganese Silicon Aluminum Bronze alloy and CNC machined to exacting tolerances. BC guides are resistant to cracking and corrosion, while reducing friction and insures high lubrication even at elevated engine temperatures and rpm's. The perfect replacement to worn or damaged guides and 100% com...

BC9991 - Polaris Cam Timing & Cylinder Holding Tool

This new 2 for 1 tool from BC functions as a camshaft timing plate for both the Polaris RZR XP Se...

This new 2 for 1 tool from BC functions as a camshaft timing plate for both the Polaris RZR XP Series (XPT, XP1000, XP900) and the Pro R cylinder heads as well as a cylinder hold down tool for the Polaris RZR XP's during engine assembly. The steel inserts are designed to hold the camshafts snuggly in place at TDC, unlike the aluminum sheet versions out there that flex or bend causing the camshafts to seize in the head. The rigidity also makes it much easier to set valve lash and install the c...

BC8291-3 - Polaris XP Turbo / XP 1000 (93mm x .051”) Cometic MLS Head Gasket

MLS for O-ring cylinder jug, 93mm Bore only, .051” Thickness - Cometic three layer gaskets combin...

MLS for O-ring cylinder jug, 93mm Bore only, .051” Thickness - Cometic three layer gaskets combine advanced materials with state-of-the-art manufacturing processes to provide custom-tailored solutions to meet the needs of each individual application. The MLS head gasket is comprised of a three layer setup - Viton coated embossed spring steel outer layers surround a steel inner layer that provides support and thickness to the gasket. Embossments on the gasket allow for a proper seal around oil...

BC9091 - Polaris RZR XPT Cylinder Jug - 94mm Bore w/O-Ring, Dowel Pin

BC offers XPTurbo cylinder jugs that have been overbored +1mm to 94mm bore size and re-Nikasil p...

BC offers XPTurbo cylinder jugs that have been overbored +1mm to 94mm bore size and re-Nikasil plated. Then we hop them up with copper o-rings and .500" dowels that mate to the cylinder head to keep both from shifting at high boost levels. We choose the XPT cylinders because of the closed deck design and the fact that they're +.050" taller deck height. This adds rigidity and support to the cylinders as well as delivering less piston side loading with an optimal compression height design pist...

BC8878-E - NEW Polaris Adjustable Cam Gears - Exhaust for XPTurbo, XP1000, XP900, 570

Machined from hardened steel alloy and fully compatible with the stock Polaris timing chain (BC h...

Machined from hardened steel alloy and fully compatible with the stock Polaris timing chain (BC has new Cloyes timing chains also), the BC adjustable cam gears for the Polaris RZR platform are the perfect way to gain top end or low end torque depending on how you dial in the gear settings. Separate intake and exhaust gears to avoid confusion, these gears allow for 5 degrees of advance or retard for both intake and exhaust cams with easy to read indicator marks. If running with BC cams, which ...

CP9051 - Polaris XP Turbo (16-up) CP Shelf Pistons w/All Hardware - 93mm x 9.5:1

Pistons are the backbone of any true hardcore racing engine and that’s where CP-Carrillo excels. ...

Pistons are the backbone of any true hardcore racing engine and that’s where CP-Carrillo excels. Our Engineering department started off analyzing the competition, gathering industry data and deciding to make the highest level of pistons, period. The heart and soul of our pistons are built through our Engineering Department and its resources. This department is made up of several factors that push them ahead of the competition; Reverse Engineering, Design Experience and Flexibility, Analysis a...

BC3992 - Polaris XP Turbo / XP 1000 Valve Stem Seals for BC3966 Valve Guides

BC valve stem seals are designed for BC’s exclusive, threaded end valve guides (BC3966). These Vi...

BC valve stem seals are designed for BC’s exclusive, threaded end valve guides (BC3966). These Viton seals allow a carefully defined amount of engine oil from the cylinder head into the combustion chamber—to lubricate the rotating valve stem in the valve guide. BC valve stem seals are produced from high performance materials for increased part life and lower wear.

BC4900 - Polaris XP1000/XPTurbo Main Bearings (oversize)

New King main bearings for the Polaris RZR platform are now available. The BC 4340 billet XP cra...

New King main bearings for the Polaris RZR platform are now available. The BC 4340 billet XP crankshafts are an improvement to the rod bearing failures but they aren’t the cure for the oiling issues. These exclusive mains from King Bearing however do provide the proper oiling from the mains to the rods with some qualified machining. King XP line bearings are a hardened coated race bearing vs the OE soft Babbitt bearing. To thoroughly “bulletproof” the case, we designed an oversize O.D. (1.75...

BC5911-75B - Fully Balanced Polaris XP Turbo (16-up) Stroker Crankshaft 75mm w/270° Crank Pin

75mm XP Turbo (270° pin) Stock Stroke - This crank comes fully system balanced to customer bobwei...

75mm XP Turbo (270° pin) Stock Stroke - This crank comes fully system balanced to customer bobweight specifications. CNC machined from 4340 billet round bar. All cranks are stress relieved, shot peened, magna flux inspected and nitrided (multi step heat treatment) for ultimate performance. Fully profiled counterweights, rod and main journals are finish sized to work with blue or green Polaris bearings using aftermarket rods. These cranks must be fully system balanced prior to installation due...

BC5910B - Fully Balanced Polaris XP Turbo (16-up) Stock Stroke Crankshaft 68mm w/270° Cran...

68mm XP Turbo (270° pin) Stock Stroke - This crank comes fully system balanced to customer bobwei...

68mm XP Turbo (270° pin) Stock Stroke - This crank comes fully system balanced to customer bobweight specifications. CNC machined from 4340 billet round bar. All cranks are stress relieved, shot peened, magna flux inspected and nitrided (multi step heat treatment) for ultimate performance. Fully profiled counterweights, rod and main journals are finish sized to work with blue or green Polaris bearings using aftermarket rods. These cranks must be fully system balanced prior to installation due...

BC0915-75 - Polaris XP Turbo (16-up) Stroker Kit 75mm w/BC Pro625+ Rods, Custom Pistons

Polaris XP Turbo - Includes 4340 billet crank, 75mm stroke, BC Pro625+ rods (4.915" c-to-c), cust...

Polaris XP Turbo - Includes 4340 billet crank, 75mm stroke, BC Pro625+ rods (4.915" c-to-c), custom CP, JE or BME pistons (choice of bore/compression). Crank # BC5911 - 75mm (270° pin) Rod # BC6912 - 4.915" Piston # BC7911 - 93mm x 9.5:1

BC0915 - Polaris XP Turbo (16-up) Stroker Kit 72.5mm w/BC Pro625+ Rods, Custom Pistons

Polaris XP Turbo - Includes 4340 billet crank, 72.5mm stroke fully balanced, BC Pro625+ rods (4.9...

Polaris XP Turbo - Includes 4340 billet crank, 72.5mm stroke fully balanced, BC Pro625+ rods (4.915" c-to-c), custom CP, JE or BME pistons (choice of bore/compression). Crank # BC5911 - 72.5mm (270° pin) Rod # BC6912 - 4.915" Piston # BC7911 - 93mm x 9.5:1

BC5910 - Unbalanced Polaris XP Turbo (16-up) Stock Stroke Crankshaft 68mm w/270° Crank Pin

WARNING - These crankshafts are not balanced. Balancing required for operation. 68mm XP Turbo (27...

WARNING - These crankshafts are not balanced. Balancing required for operation. 68mm XP Turbo (270° pin) Stock Stroke - CNC machined from 4340 billet round bar. All cranks are stress relieved, shot peened, magna flux inspected and nitrided (multi step heat treatment) for ultimate performance. Fully profiled counterweights, rod and main journals are finish sized to work with blue or green Polaris bearings using aftermarket rods. These cranks must be fully system balanced prior to installation ...

BC3965-E - Polaris XP Turbo (16-up) / XP 1000 (14-up) Exhaust Valve Guides (BC Design)

BC premium valves guides are made from Manganese Silicon Aluminum Bronze alloy and CNC machined t...

BC premium valves guides are made from Manganese Silicon Aluminum Bronze alloy and CNC machined to exacting tolerances. BC guides are resistant to cracking and corrosion, while reducing friction and insures high lubrication even at elevated engine temperatures and rpm's. The perfect replacement to worn or damaged guides and 100% compatible with BC's lineup of stainless steel valves.

BC3805 - Polaris XP Turbo (16-up) / XP 1000 (14-up) Stainless Steel Exhaust Valves - 32.4m...

BC valves are one piece design with a friction welded Stellite tip for the best possible performa...

BC valves are one piece design with a friction welded Stellite tip for the best possible performance. Every valve is made from premium grade, heat resistant stainless steel material to insure reliability with high boost and/or high rpm applications. The undercut stem above the head area not only reduces overall weight for extended rpm potential, but also significantly improves air/fuel flow in and out of the combustion chamber. Every valve is fully machined and features a swirl polished finis...

BC0919 - Polaris XP Turbo (16-up) Stroker Kit 78mm w/Custom MOAR Rods

Polaris XP Turbo - Includes 4340 billet crank, 78mm stroke, MOAR rods (4.921" c-to-c) w/custom ro...

Polaris XP Turbo - Includes 4340 billet crank, 78mm stroke, MOAR rods (4.921" c-to-c) w/custom rod journals, and choice of CP or JE shelf pistons (choice of bore/compression). Crank # BC5915 - 78mm (270° pin) w/42mm Pin Rod # BC6999 - 4.921" w/45mm BE Bore, .787" PE Bore Piston # CP or JE - Custom in any bore/compression

BC0917 - Polaris XP Turbo (16-up) Stock Stroke Kit 68mm w/Pro625+ Rods, Shelf Pistons

Polaris XP Turbo - Includes 4340 billet crank, 68mm stroke, Pro625+ rods (4.915" c-to-c), choice ...

Polaris XP Turbo - Includes 4340 billet crank, 68mm stroke, Pro625+ rods (4.915" c-to-c), choice of CP or BME shelf pistons. Crank # BC5911 - 68mm (270° pin) Rod # BC6912 - 4.915" Piston # CP or BME - Shelf 93mm x 9.5:1

BC8291-5 - Polaris XP Turbo / XP 1000 MLS for O-Ring Cylinder Jug & 1/2" Dowels (93/94mm x...

MLS design fits 93mm or 94mm bore, .036” Thickness - Cometic MLS design gasket for use on BC O-ri...

MLS design fits 93mm or 94mm bore, .036” Thickness - Cometic MLS design gasket for use on BC O-ring cylinder jugs. Also features .504" ID alignment holes for BC's dowel pinned cylinders. Three layer gaskets combine advanced materials with state-of-the-art manufacturing processes to provide custom-tailored solutions to meet the needs of each individual application. The Multi-Layer Steel gaskets are comprised of multiple embossed layers of both proprietary high temperature coated and uncoated s...

BC9913 - NEW Polaris ProXP Turbo CNC Cylinder Head - Big Port 38.8mm/33mm Valves

Use pulldowns above to build out your head. The BC core exchange program works three ways: 1) Buy...

Use pulldowns above to build out your head. The BC core exchange program works three ways: 1) Buy one of BC's new heads outright, no exchange. 2) Send a new head in for even exchange for one of BC's new "in-stock" heads. 3) Send a used head in, receive that same head back. BC only accepts new, never-been ran Polaris ProXP Turbo (#3023564) cylinder heads as new core exchanges. BC uses only new ProXP heads for all new even exchanges. All heads come with BC bronze valve guides installed as well ...