1967 cylinder heads

[Donald O.]

On a 1967 327350hp what size is the chamber?
In trying to select the closest match to the domed OE for the 11:1 ratio for a restoration rebuild, all of the parts offerings will give a ratio with a value in CCs; examples:
Kieth Black
Chevy 327ci Hypereutectic Pistons Solid Dome .100''
4.030'' Bore (+.030'')
Use w/5.700'' Connecting Rod & 3.250'' Crank Stroke
Comp. Ratio: 11.3/58cc; 10.7/62cc; 10.5/64cc; 9.1/76cc Head


Speed Pro
327ci Stock Type Piston, .030'' OverborePiston Dia: 4.030''
Piston Top: .125'' Dome with 2-Valve Reliefs
Pressed Pin
Comp Ratio: 10.35:1 w/64cc Head
Ring Grooves: 5/64'', 5/64'', 3/16''


Both CRs are as measured with the 0.040 composite head head gasket, not the 0.015 steel shim OE type.
So what did the General use on the 1967 L79 for the heads?

DonO

[Patrick B.]

Re: 1967 cylinder heads

1967 327 heads are 462 castings that have 64 cc chambers.

[Gene M.]

Re: 1967 cylinder heads

On a 1967 327350hp what size is the chamber?
In trying to select the closest match to the domed OE for the 11:1 ratio for a restoration rebuild, all of the parts offerings will give a ratio with a value in CCs; examples:
Kieth Black
Chevy 327ci Hypereutectic Pistons Solid Dome .100''
4.030'' Bore (+.030'')
Use w/5.700'' Connecting Rod & 3.250'' Crank Stroke
Comp. Ratio: 11.3/58cc; 10.7/62cc; 10.5/64cc; 9.1/76cc Head


Speed Pro
327ci Stock Type Piston, .030'' OverborePiston Dia: 4.030''
Piston Top: .125'' Dome with 2-Valve Reliefs
Pressed Pin
Comp Ratio: 10.35:1 w/64cc Head
Ring Grooves: 5/64'', 5/64'', 3/16''


Both CRs are as measured with the 0.040 composite head head gasket, not the 0.015 steel shim OE type.
So what did the General use on the 1967 L79 for the heads?

DonO

The General used steel shim gasket. But I think GM was optimistic about the 11:1 compression as most head and piston combo are far from optimal in achieving it.