'42 bell housings have a different bolt pattern than later that have a GM bolt pattern like your T-5, unless it is a Ford bolt pattern. All that matters is retainer diameter-they both must match; input shaft stickout; and bolt pattern. '42 or early bellhousings may be easily drilled out if other dimensions match. Perch the trans on top of the bellhousing, use a transfer punch to locate mount holes in bellhousing, take part, drill and tap holes marked in 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.