JE Pistons new GM LS flat top Asymmetrical FSR (Forged Side Relief) forging design allows for the use of the most popular stroke and rod combinations while eliminating reluctor wheel clearance problems. Asymmetrical forging design maintains a larger skirt on the heavily stressed major thrust side, while reducing friction with a smaller skirt on the minor thrust side. The result is a high strength, lightweight piston that significantly reduces friction in your engine. Lightweight and extremely durable, JE pistons are machined for 1.2mm, 1.5mm, 3.0mm rings.
Combination 12° & 15° Valve Pockets

Includes:

Grain Flow Optimized Forging

Lateral Gas Ports

Ceramic Crown Coating

Perfect Skirt Coating

Accumulator Groove

Double Pin Oiling

Upgraded 9310 Pins and locks

Compression Ratio:

64cc 10.6:1

68cc 10.2:1

70cc 9.9:1