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#97775 12/10/20 10:50 PM
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Al Offline OP
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A friend put me on to this web site. It talks about early GMC straight 6 engines of large cubic inches.
We are talking 360, 426, and 503 cubic inches. I had never heard of these engines. Anybody know if any of these were hot rodded?
https://www.curbsideclassic.com/blog/cc-...ly-big-gmc-six/

Al #97776 12/11/20 12:02 AM
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Lets put an 8-71 on it and stuff it in an AD half ton. Is the 503 something that can be found?

Al #97779 12/11/20 03:10 PM
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Those are BIG truck engines and will not fit in much else. The 360 is the only one that would even qualify for the vintage class at Bonneville since there is a 375" limit. Years ago I got a 413ci Dodge flathead six with the Idea of playing with it in a vintage class at Bonneville. There is a 375" version of it, just a crank change. smile Otherwise it would be in BG lakester and tires aline would be over 3Gs. I even had an Honest John missile nose cone for it. laugh

I doubt that performance wise the extra size and weight would be helped by the extra inches. Maybe I'm wrong.


"I wonder if God created man because he was disappointed in the monkey?" Mark Twain
Al #97780 12/11/20 05:19 PM
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W/r/t "I doubt that performance wise the extra size and weight would be helped by the extra inches"

I agree, these engines have much smaller port and valve area per cubic inch than the 302 etc. and were designed to operate at very low engine speeds.

Al #97785 12/12/20 09:12 PM
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Thanks for the info.
Would still like to see one of those big ones in operation.


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