Engine SN stamped on cast block, right side, rear, near starter, starts w/ engine displacement, I. E. 302xxxx, 270xxxx. Probably has a Clark 5 speed, if tin is good, get it running and sell to someone who likes large trucks, would be a shame to part out if tin is good.

I also have a '54, first series, that has a 503. 650 MN.

Last edited by EdPruss; 07/26/2015 8:02 PM.
'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.