GPI 4.070? Bore LT1 Piston (Standard Compression) - 801GWA
Oversize 4.070" LT1 Piston for Strong, Reliable Gen 5 Builds
The GPI 801GWA 4.070? Bore LT1 Piston is a precision-engineered oversize version of GPI's proven standard-compression drop-in piston design. Expanded by .005" to a 4.070" bore, this piston is ideal for LT1 engines needing a light overbore while maintaining factory-style compression characteristics and excellent durability for high-performance street and track builds.
When paired with the Callies Compstar connecting rods (CSC6125DSA2AH), these pistons remain a true "no balancing required" solution, preserving OE smoothness while offering the strength required for aggressive use.
Technical Notes & Clearance Guidance
A .040? minimum gasket thickness may be used. When milling cylinder heads:
- Milling more than .030?: Check piston-to-chamber clearance.
- Milling more than .040?: Use a non-extended-tip spark plug (Brisk RR14 / RR12 / RR10 recommended) along with Moroso indexing washers to prevent the plug tip from contacting the piston dome.
Important Compatibility Warning
These pistons will not fit OEM 6.098 connecting rods. They require the Compstar rods mentioned above for proper installation and balance characteristics.
Performance Highlights
- Based on GPI's standard-compression LT1 drop-in piston
- Machined to 4.070? bore for light overbore applications
- No balancing required when used with CSC6125DSA2AH rods
- Compatible with .040? minimum gasket thickness
- Safe for high-RPM, boosted, or aggressive N/A builds
Quick Specs
- Part Number: 801GWA
- Bore Size: 4.070?
- Piston Type: Standard Compression
- Compatible Rods: Callies Compstar CSC6125DSA2AH
- Non-Compatible Rods: OEM 6.098? LT rods
- Minimum Gasket Thickness: .040?
FAQs
Does this piston change the LT1's compression ratio?
No. It maintains the standard compression characteristics of GPI's drop-in LT1 piston design - only the bore size has been increased.
Can I use these pistons with factory LT1 connecting rods?
No. They will not work with OEM 6.098 rods. They are engineered specifically for use with Compstar CSC6125DSA2AH rods.
Why Buy from Beefcake Racing?
Beefcake Racing supplies trusted GPI engine components backed by real performance expertise. Need help selecting pistons, rods, or a full short block combo? Call 1-855-827-7223 or email sales@beefcakeracing.com.
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