| Crusing in the Passing Lane Joined: Jun 2011 Posts: 5,096 | 550’s are OK, however, to get OD, the third gear position is removed, so shifting skips that ratio which limits on to second gear if one has a load. Short GM input shafts are not available, however GM used a special bell housing that takes the long input shaft and 14” clutch, I have one if anyone needs the casting number.
If one finds an early 4500, it will come with stock GM bolt pattern and right length input shaft, or use Dodge input shaft and 1” thick adapter plate as member just above did.
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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