CLASS RACER FORUM - 727 W/ 904 internals

A "fit all" (fit all meaning fits both Chevy as well as BOPC) TH350C (lock up) case is quite common, the old "fit all" PoweGlide case is rare, but not unobtainable. I have not personally seen a "fit all" TH 400 case, nor had I heard mention of one until now. The 200 4R was only available as a "fit all", most of the TH250C cases were "fit all" as well, and as Mark mentioned, the 700 R4/4L60/65E only came with a Chevy pattern.

In the case of putting a Chevy case behind a BOPC engine, or the reverse, TCI made a thin steel adapter to do it with. The engine families share the same location for the bottom two bolt holes as well as the two dowel pin holes. All you need to do is make up the differences in the top 4 bolt holes. I ran one in my Cutlass when I was developing the 700 R4 for serious street/strip use, as I had a 455 Olds engine in it.

There is no performance advantage to be gained by using a Chevy case behind a BOPC engine for a TH350, a TH400, or even a Metric 200, nor is the reverse, a BOPC case behind a Chevy engine, true.

The Chevy TH400 case has become pretty rare, I have a few that I will not sell unless I sell them as a complete race transmission, and maybe not even then. However, now the BOPC cases have become rare as well, as the crusher is getting 95% of everything built before the mid nineties, many salvage yards do not even pull anything other than the fuel tank before crushing.