Keep your stock crankcases and max out the horsepower of your late Big Twins. Wrinkle black finish. Gear drive 640 Easy Start cams included in kits. Wrinkle black powder-coat finish heads match factory finish. Stroke 4-5/8", bore 4-1/8", cylinder length 5.013". Made in USA.. Requires crankcase boring to accept 4-1/8" cylinders. Minimal engine height change: .096" and original serial numbers retained. Kits include S&S super stock 91cc cylinder heads 10.8:1 CR.
