The Th350 is basically a square with a corner taken out of it. See for yourself. The TH400 on the other hand has 9 different angles on the the pan. It’s one of the more complex pans that GM made. Notice how regular the TH400 pan is irregularly shaped . See how the Turbo 350 has a very simple pan with 13 bolts. The Turbo 350 has a much simpler ...
Source Code transmission-3.00.tar.xz Nightly tarballs Previous tarballs How to build. Windows (early preview) transmission-3.00-x86.msi transmission-3.00-x64.msi Requires Windows 7 or later Nightly builds.
These should all be built to the same torque and horsepower specs. Before the Getrag, GM used a Muncie 4-speed and an Isuzu 5-speed in these vehicles. Some information on the Getrag as of 1989: HM-282 (5TM40) 200 lb/ft maximum torque 88 lbs. dry weight 7000 RPM Maximum input speed
The price of a new one is almost the same for a conversion and a TH350 transmission. The payback is 5 years down the pike when you need an overhaul or a new transmission. The TH350 can be had almost anywhere in the world for 1/3 the price of the lesser BW66.