Centre main cap 4 bolt type not “s” special fitment only

Steel 4-bolt center main cap for large bore engines (not ‘S’). Comes with correct length HT bolts. On all performance A series engines it is essential to ensure as accurate location of the center main bearing of the crankshaft as possible. Flex allowed here, especially at sustained high RPM levels, can cause spun bearings, crank or main cap breakage with severe or mortal damage to the engine. This specially machined cap provides the ultimate center main location, essential for all stroked engines. Requires line boring, and two extra holes drilled into the block and tapped 7/16″ UNF. The thrust faces are part machined for final finishing while the line boring is being done.Bolts on one way only so take care to read instructions.