| Crusing in the Passing Lane Joined: Jun 2011 Posts: 5,096 | Back to the 248 manifold issue, GMC's used two different size intake port sizes, so, while one port size manifold will fit all, not the best fit. Early(smaller) engines were smaller. Patrick's old catalogue has data.
Ed
Last edited by EdPruss; 04/27/2017 4:07 AM.
'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires.
'47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle.
'54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed.
'55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.
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