FixVault

Engine Compression

Before making a compression test or cranking engine with a remote starting switch, disconnect ignition switch connector (Pink wire) from HEI system distributor. Test compression with engine warm, all spark plugs removed and throttle and choke valves wide open. Crank engine through at least 4 compression strokes.

ENGINE COMPRESSION

Application Specification
Compression Ratio
  260" 8.0-1
301" 8.2-1
305" 8.4-1
350" (VIN E, H, J & M) 7.6-1
350" (VIN L) 8.2-1
350" (VIN P) 7.6-1
350" (VIN R) 8.3-1
350" (VIN X) 8.0-1
400"(VIN Z)
    Standard 7.7-1
High Performance (1977-79 Only) 8.1-1
  403" (VIN K)
    1975-77 7.6-1
1977 8.5-1
1978 7.9-1
1979 8.3-1
Recommended Fuel Unleaded (87 AKI Minimum)
Compression Pressure (All) 120-160 psi
Max. Variation Between Cylinders 30%