Chevrolet LS, -18cc dish top.

Application: 

Recommended for applications using nitrous (up to 250HP shot) / boost (up to 10LBS). Image is a representation of this item. Actual item may vary.

Includes: 

Complete set of pistons, locks, pins & oil rail spacers (as required). 

Specifications:

Piston top type: (-18cc) dish top.
Bore: 3.908" to 4.130".
Stroke: 3.622" & 4.000".
Rod length: 6.125".
Compression height: 1.110" & 1.299".
Compression ratio (64): 9.0 to 10.5
Compression ratio (70): 8.5 to 9.9.
Compression ratio (72): 8.3 to 9.8. 
Dome volume: -18.
Gram weight: N/A.
Rings: 1.5mm, 1.5mm, 3.0mm.
Ring set: R5067.
Rings included: yes.
Oil rail spacer: ORS-387.
Pin type: 5115 straight wall.
Pin diameter: .927".
Pin length: 2.300".
Pin wall: .150".
Pin weight: 107.
Block height: 9.240".
NOTE: (1) Forged from high strength 2618-T61 aluminum with forged side reliefs with internal and external bracing (2) Optional pin upgrade available (3) Optional lateral or vertical gas porting available.