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