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| | | Forums66 Topics128,052 Posts1,055,770 Members48,426 | | Most Online14,466
Apr 26th, 2026 | | AD Chevy Trucks  Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
Lots of work on Brad's part ... pure enjoyment (and references) for you!
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| | | | Joined: Mar 2013 Posts: 219 'Bolter | | 'Bolter Joined: Mar 2013 Posts: 219 | does anyone know what the CCs are of a large port 302 head with the D shape combustion chamber??
THANKS Jay D. | | | | | Joined: Jan 2022 Posts: 2,446 'Bolter | | 'Bolter Joined: Jan 2022 Posts: 2,446 | I measured mine once to get an idea of what the static compression ratio would be. I'll see if I can find the numbers somewhere. If not, I'll measure again in a few days.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12
'52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
| | | | | Joined: Feb 2020 Posts: 47 'Bolter | | 'Bolter Joined: Feb 2020 Posts: 47 | Mine were 118cc. 104cc after removing .080 of the head. Also shaved the block .020 To bring the pistons level to the block. Never calculated compression ratio.
just retired and finally making headway on my project truck. 1940 GMC AC152.
| | | | | Joined: Jan 2022 Posts: 2,446 'Bolter | | 'Bolter Joined: Jan 2022 Posts: 2,446 | Using GMC-IS-ME's 118cc (7.2 cubic inches), a stock 4" bore piston that comes all the way to the deck and a 0.060" thick head gasket with a 4.060" hole the static compression ratio computes at 7.3:1
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12
'52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
| | | | | Joined: Mar 2013 Posts: 219 'Bolter | | 'Bolter Joined: Mar 2013 Posts: 219 | Thanks, just what i needed!!!!
Jay D. | | | | | Joined: Dec 2008 Posts: 1,922 'Bolter | | 'Bolter Joined: Dec 2008 Posts: 1,922 | >060" gasket means .060" quench, much too loose. You want .035-.040" | | |
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