I have also never seen a 420 on anything larger than 1.5 ton truck, larger truck(GMC) for example would have some NP-or GM or other 5 speed.

465’s different.

Ed

Last edited by EdPruss; 03/16/2023 8:55 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.