| Crusing in the Passing Lane Joined: Jun 2011 Posts: 5,096 | 4500's use a mounting bolt pattern that looks just like an earlier GM pattern, however it is slightly larger. One way to get around this problem, is to drill and tap the earlier pattern in the front of the 4500, easily done, especially if your trans is apart. Just sit the 4500 on a bellhousing, tail up. Use a transfer punch to locate the holes, remove the trans, drill and tap the holes. Best to make the bottom ones blind to avoid a bath every time they are removed.
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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