Complete bolt-on 2025cc kit. Compatible with stock 107" engines; which have the required 4.375" stroke. Converts the 107" engine to 124". Incl. black wrinkle cylinders and a forged 4.250" bore piston & ring kit with 1.143" deck height and -4.3 cc dish volume for an 11:1 CR with stock cylinder head combustion chamber volume. Incl. all required head & base gaskets and hardware. Provides a massive increase in capacity with bolt-on installation ease; no case boring; head work or flywheel re-balancing required. Note: Compatible with OEM head bolts but S&S advises the; 14% stronger than stock; 576972 S&S head bolt kit for all big bore applications.