I have a 833 manual gearbox and the retainer (the raised area) is 125mm across. The small block bell housing (pn 3545 734) is 115mm across. Is this a big block gear box? or am I missing something. I bought this set up believing it came off a small block.

What is the casting number of the bearing retainer on the front of the transmission?
Dan

Sounds like you have a large bearing 4 speed (usually used on big blocks)and a small block bell housing (for the smaller bearing housing transmission- usually used on small blocks).

Thanks for the info so far. The number on the retainer is C-15397, then a space of about 2 inches and then a stamped GJ3.

I have another box (apparantely not in operable condition) with retainer number C 13157.

Can the retainer be turned down to suit the small block bellhousing?

Thanks..Rodsports

C-15397 is the GM version of the A833 overdrive. Should have a 10 spline input.

C-13157 is the mopar version of the overdrive. 23 spline input shaft.

You can't machine all the extra off the retainer, machine it down to 4.805" and machine the bell to 4.807".
Dan

Dan, Thanks Mate, I appreciate the info and help.