As I recall, I cut off a piece of early bellhousing with brake and clutch mounts, cut off part of later bellhousing and welded in place using Ni rod, pre and post heat, works great.

Bellhousing can be bored out to fit 420 retainer., not on a drill press.

Seems like early trans did not have bottom right mounting hole ofset to right, easy fix, mount trans with others, mark hole from bellhousing in trans, drill and tap early mounting hole on late bellhousing.

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.