Yes thay are.
Yep! The transmissions are completely interchangeable.
Yes thay are the same.
Only if the transmission has a dual bolt pattern. Chevrolet and Buick 350 engines have the same bolt pattern. Oldsmobile and Pontiac 350 engines have the same bolt pattern. There were some TH 350 transmissions that have dual bolt patterns.
Yes of course. All Chevy engines are interchangible with transmissions. For example, you can have a 305, 307, 327, 350, 400 with a turbo 350, turbo 400, or 700r4 big block are also the same
The starters are compatible with both engines, just the 350 starter will probably put out more torque than the 305.
Any size SBC engine will fit and is compatible with a 91 Firebird. A 350 engine is the most common that is used for installing in a 91 Firebird.
The Buick 350 V8 engine and the Chevrolet L6 and V8 engines share the same bolt pattern. Pontiac and Oldsmobile 350 V8 engines share their own bolt pattern. There were also TH 350 transmissions that had dual bolt patterns and fit all 350 GM engines.
The bolt pattern on Chevy engines is unique. There are TH350 transmissions with both the Chevy bolt pattern and the BOP (Buick, Olds, Pontiac) pattern, but they are becoming somewhat rare.
It will fit right in the 99 as long as it is not the new body style. In late 1999 Chevy redesigned the engines and transmissions and no longer used the 5.7L 350 engines.
turbo 350 or 700r4 turbo 350 or 700r4
Chevy 350 engines are bored to a 4 inch bore.