Yes it is a small block and NOT an LT1 engine. 5.7L is a 350 engine.
No they stoped making the 400 SB in 1981
It is on the back of the alternator, Disconnect the Battery first!. There is a small module on the back of alternator remove and replace.
the thermostat is located behind the alternator on the front of your engine block. you might need to remove the alternator unless you have small hands then just squeeze in there with either a hex wrench or socket and open the plastic housing up and pull the old thermostat out and replace it with the new thermostat and gasket.
replace the engine with a small block chev
Yes, assuming you're running a small block. If you're running a turbocharged engine or a big block (e.g., the 454SS pickup), the torque of that engine will greatly exceed what the transmission is rated for.
the door hinges are welded so you have to use a small hammer and small punch to tap out the pins that look like big nails.
Left side on front of motor. Follow the battery cable and it will lead you right to it.
Some do, some don't. The distributor, starter and alternator fit, the water pump does not. The mounting brackets are all different.
You will need to remove the transmission.
On older models, it was usually on the core support or inner fender. From the early 70's it was inside the alternator.
Need to know the year of engine.