I replaced the 259 gasser in my '37 GMC 2 ton, replaced the steering box and running gear with GMC P3500 HD axles, Saginaw box and hydroboost brake. Retained original steering wheel, mast and shaft through firewall. Put Saginaw box outside frame, in front of axle. RR-10 speed main box plus 3 speed Brownie. Works well.

One might look on '4btswaps'.com for diesel info.


Last edited by EdPruss; 12/14/2015 8:00 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.