Hey all, new here... my first Mopar! Few questions

Hey all, I just recently got my first little muscle car. Its a 73' Duster that came with a disassembled 318 v8, and a 3 speed auto on the floor.

The cars in fairly good shape, not much rust on the body at all, subframes have a few holes though. But recently I just picked up a 1969 383 big block with the 3 speed auto tranny, 54k original miles on the combo, guy pulled it from the car and sold it to me for 350$. Only thing the engine needs is a starter he says.

First question, will the 318 starter fit the 383?

I'm going to be buying that motor mount kit for 160$, that bolts the 383 right up. I also know I'll need some stiffer torsion bars?

Any tips on what to check for on this motor? Since it is 41 years old, before it would be safe to use? It was running 4 years ago the owner said.

I plan on removing the AC from the engine, am I going to have to remove anything from the engine bay to make this thing fit?

Thats all I can think of at the moment! Any tips, hints, or links that will help, feel free to shoot them this way!