| Crusing in the Passing Lane Joined: Jun 2011 Posts: 5,096 | Sometimes there are numbers stamped on the housing out near the spring hangar. To find ratio, jack up one wheel, count driveshaft vs wheel revs., make sure you know hi or low.
Ed
'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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