For 96" to 103" (3 3/4" to 3 7/8") big bore conversions. Used with stock heads and cylinders. By boring the stock cylinders from 3-3/4" to 3-7/8" big bore size engine capacity will increase from 96" to 103". Comes with T6 heat treated 390 Hypereutectic cast pistons with 16% silicone levels which enables running a very tight clearance for longevity and hardly any piston noise.

10.0:1 CR with 85cc head. Head type: Flat top.

+1.9cc / Compression height 1.076".

Bore 3.875" / Stroke 4.375".

Rod length 7.667".

Note: Top compression ring will need additional clearance. See instructions.