This big bore, stock stroke “square” engine kit develops an excellent balance of torque and horsepower that delivers lots of arm stretching fun. The kit is supplied with Zipper’s aluminum big bore cylinders with cast-in ductile iron liners, fitted with our special 3-13/16” bore forged pistons that eliminate the need to rebalance the crankshaft, Red Shift cams, Pro-Taper moly pushrods and telescoping pushrod covers, along with CNC-ported cylinder heads equipped with oversize valves. These heads feature fully CNC-machined combustion chambers that match the pistons perfectly. Special hardware and a full gasket set are included. Rounding out this powerful package are high flow injectors and air filter element and a pre-mapped ThunderMax® EFI management module for simple plug-and-ride tuning!
Zipper’s Performance Products offers two versions of this kit. One with emphasis on the lower and middle ranges of power (Big Torque) and one that shines on the upper end of the RPM scale (Big Horsepower).