I got a 70 Belvedere Wagon with the /6 and a 3 speed tranny.
I found out the hard way that a similar tranny from a V8 don't work real good.
I forgot the old adage- "Measure Twice, Cut once"
I wasn't cutting nothing but I forgot to do some preliminary measurement before installation. That story can end here...

What I need for the matching replacement is:

*23-1/4 overall length of casing
*15" Tail Housing
*Inspection Cover on the top side
*1-1/8" Diameter output output shaft
*26 Spline

Any help on the info I need would be paid forward ASAP

Thanks,
Rennie