| Crusing in the Passing Lane Joined: Jun 2011 Posts: 5,096 | The GO's are really rare, I would use the 292, w/ the 5 speed, it is more useful, especially w/ a load, to be able to use 4th. on steep hills, rather than let the speed bleed off to 30 or so for 2nd on a 420. 9:1 propane pistons are available for 292's.
Your 540 might have the long input shaft, > 7", mix and match that bellhousing, flywheel, clutch, etc., to make it work.
I had an early Bronco, that I put a 540, Buick even fire 231 V6, 350 rear, very useful combination, hauling up to 14,000 GVW, that 5 speed made it work well.
Might look at slightly higher rear ratio depending on empty/loaded use.
'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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