NEW CRANKCASE FROM BC (#420893001) - Keep your existing crankcase and save some time by getting a new BC supplied case that's typically in stock and ready for immediate delivery. CSS has developed a proven technique for strengthening OEM aluminum open deck blocks. Proven in 1200+whp Honda 4-cylinder engines, the CSS support system is perfect for the open deck Can-Am X3’s. The BC/CSS case features a +1mm oversize bore (75mm but also available in 74.5mm bore) for added displacement, copper O-Rings to contain combustion and drilled & tapped head stud holes to accommodate BC custom ARP head studs (AR8699). These studs feature 7/16” diameter, coarse thread (1.75) into the case and 7/16" diameter into the head (machine work req). The most common issue with X3 cases at bigger power levels is pulling the threads out of the upper case half. These coarse thread studs deliver proper clamp load without pulling the threads, offering proper sealing of the cylinder head using the Cometic MLX head gasket (also available from BC).