Forged piston set. For 41-78 1200cc (74") Knuckle, Panhead, Shovel and 1340cc Shovel. Fits engines with stroker flywheels and stock 3-7/16" (1200cc) or 3-1/2" (1340cc) cylinders with stock 5.330" length. Compression will be approx 8.4:1 with 4-1/2" stroke, 9.4:1 with 4-5/8 stroke and 10.8 with 4-3/4" stroke. Piston dome volume 50cc. The advanced alloy and piston skirt profile for low noise and long engine life. Pistons include wrist pins, wrist pin clips and piston rings. Note: +.060" 3-7/16" bore of the 1200 engine is identical to the standard 3-1/2" bore of the 1340cc engine. Note: In any and all applications the technician must be able to judge components for their suitability in combination with the other engine components, prior to installation. It is of importance that a knowledgeable mechanic will install & make adjustments as required. The rider must follow standard break-in and riding procedures for overhauled engines.

Fits: > 41-84 B.T. with 84" (4-1/2" stroke), 86" (4-5/8" stroke) & 88" (4-3/4" stroke) engines