valve body interchange ? 46RH-46RE

i recently acquired a pair of 46RE transmissions, and noticed the casting numbers on the case near the bellhousing are the same as the casting numbers on the 46RH transmission i have.
also, the 8 pin and 3 pin connector holes look to be in the same location [i haven't measured to be sure] and appear to be the same diameter coming through the case.

my question is, what are the differences in the internal case machined surfaces and passages that prevent valvebody interchanges between the RH and RE valvebodies ?

i also know cope has manual valvebodies for the RE transmissions. would one of his valvebodies be too harsh for a mild street application in a truck ?

as is ALWAYS the case, a big TIA in advance for any thoughts or comments on this subject.

I haven't compared the two but, since the RE has no mechanical governor, it's likely that the drilled passages for the governor in the rear of the case aren't in the RE case.

THANKS john !
so it "may" be possible to machine the case for the governor passages, in which case, i can accomplish with no problem.
if a guy were to use a transgo manual kit for an RH valvebody, would that still necessitate the governor passages in the RE case ?

cope sells a manual valve body that should fit the re transmissions as well.