GPI 4.070? Bore LT1 Piston (Lowered Compression) - 901GWA
Oversized 4.070? LT1 Pistons with Lowered Compression for Boosted Builds
The GPI 901GWA 4.070? Bore LT1 Piston is the enlarged (.005? oversize) version of GPI's proven LT1 drop-in piston, designed for builders needing a light overbore while targeting a lower compression ratio - ideal for supercharged, turbocharged, and nitrous applications. Featuring a dish design and an effective volume of - 14.5cc, these pistons deliver a boost-friendly 10.25:1 compression ratio in Gen 5 LT1 / L86 6.2L engines.
When paired with the Callies Compstar connecting rods (CSC6125DSA2AH), they remain a no-balancing-required solution, maintaining OE smoothness while providing the added strength needed for high cylinder pressure builds.
Technical Notes & Compatibility
- .040? minimum gasket thickness can be used
- Lowered compression ideal for forced induction and high-load applications
- These pistons will not fit OEM 6.098? connecting rods
- Balancing required with any rod other than the specified Compstar rods
Performance Highlights
- 4.070? bore (.005? oversize) for light overbore LT1/L86 builds
- Dish piston design offering reduced compression
- 10.25:1 ratio optimized for boost or nitrous
- Effective volume: - 14.5cc
- No-balance installation only with CSC6125DSA2AH Compstar rods
- Built for reliability under high power and high cylinder pressure
Quick Specs
- Part Number: 901GWA
- Bore Size: 4.070?
- Piston Type: Dish - Lowered Compression
- Compression Ratio: 10.25:1
- Effective Volume: - 14.5cc
- Drop-In Fit With: Callies Compstar CSC6125DSA2AH rods
- Not Compatible With: OEM 6.098? rods
- Minimum Gasket Thickness: .040?
FAQs
Is this piston setup ideal for boosted LT1 builds?
Yes. The reduced 10.25:1 compression ratio and dish design make these pistons excellent for supercharged, turbocharged, or nitrous combinations.
Does this piston require engine balancing?
Not when paired with CSC6125DSA2AH Compstar rods. Any other rod choice will require balancing.
Why Buy from Beefcake Racing?
Beefcake Racing is a trusted source for GPI internal engine components, offering expert recommendations for LT1/L86 engine builds - from drop-ins to full forged setups.
Need assistance? Call 1-855-827-7223 or email sales@beefcakeracing.com.
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