This is a genuine factory GM 400 Small Block Chevy (SBC) bare engine block, engineering casting number 330817. This heavy-duty cast iron block was the mainstay for Chevrolet’s full-size cars and trucks throughout the 1970s. It features a robust 2-bolt main design and 3-freeze plug configuration, making it a highly sought-after core for performance "stroker" builds (such as a 406 CID) or period-correct restorations.
Specifications
Bore x Stroke: 4.125 in x 3.75 in (Standard).
Main Journal Diameter: 2.65 inches (Large Journal).
Design: Siamesed cylinder walls (standard for 400 SBC) requiring steam holes in cylinder heads.
Casting Number: 330817 (Found on the driver-side rear bellhousing ledge).
Vehicle Compatibility
This casting is a direct fit for 400 CID V8 applications from 1972 to 1980:
Chevrolet / GMC C/K Trucks & Blazers: 1973–1980.
Chevrolet Caprice / Impala / Monte Carlo: 1972–1976.
Chevrolet Chevelle / El Camino / Laguna: 1973–1976.
Condition & Inspection Details
Hot-Tanked & Cleaned: This block has been professionally hot-tanked and thoroughly cleaned. It is free of grease, heavy scale, and road grime, allowing for immediate inspection and machine work.
Thorough Inspection: This unit has been physically inspected for:
Housing Integrity: Checked for external cracks, damaged mounting ears, or freeze plug bore failures.
Cylinder Walls: Visually scanned for deep scoring; appears to be at a rebuildable bore size.
Main Caps: Includes matching original 2-bolt main bearing caps.
Important Note: This is a bare engine block with main caps only. While it has been cleaned, we always recommend a professional Magnaflux crack detection and final machine shop verification (honing/boring) before final assembly.
Shipping Information
Method: Ships via Freight on a secured wooden pallet.
Total Weight: Approximately 250–275 lbs including pallet.
Notice: All fluids have been drained. Delivery to a commercial address with a forklift or loading dock is recommended to avoid residential liftgate fees.
California Proposition 65 Warning
⚠️ WARNING: This product can expose you to chemicals, including lead and mineral oils, known to the State of California to cause cancer and birth defects or other reproductive harm. For more information, go to the official P65Warnings website.