| Crusing in the Passing Lane Joined: Jun 2011 Posts: 5,096 | There are not significantly higher rear gears, only slow and slower. Look for a Brownie for an OD ratio. 5000 series work fine-somewhat hard to find, 6000 series OK, just larger.
Make sure valves are not stuck before turning over, otherwise might break rocker arms.
Original brakes not up to very high. speed, especially w/ load. Read here about front disc conversions, using 2 ton front axle.
Can get later 235 or 261 engine, full pressure oiling.
Later 5 speed trans(NP-540 series) for example has close ratios.
NV-4500 great OD trans
'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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