No difference at all.
Th350 has a modulator on the back. Th400 has modulator on side. 700R4 has no modulator.
Yes, it was available.
That would be the 4L80E automatic transmission.
Manual transmissions usually don't --- Automatic transmissions almost always do.
6-speed automatic. Technically 5 speed with overdrive
Both automatic and manual 5.0
They were not tightened properly.
The optional transmissions were the Powerglide, the Turbo-Hydramatic 350 and 400.
There is not a gear in the engine, they do have a speed limiter in the computer. Also some older automatic transmissions have a "governor" to adjust shift points.
The Chevy 283 engine has the standard bellhousing configuration and is compatible with transmissions that bolt to first generation small blocks. The automatic TH350 transmission will fit the 283 engine.
There are several GM automatic transmissions that have the Chevy bolt pattern. Powerglide, TH200, TH2004R, TH350, TH375, TH400, TH700R4. These same transmissions also came with the BOP bolt pattern, so make sure you get one from a Chevy.
Turbo Hydra-Matic 700.