Dan, Got the brochure for a T18H, only shows a 239, of which I have one that I replaced w/ a 453-T, do not show any other engine, my 3 piece engine in my other T18H could be a 360, held my 2 carb manifold for 426 and 503 along side it, has wider port spacing than subject 3 piece engine. Have px if anyone has other ideas.

Happy New Year to all.

'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.