74 to 65 Drivetrain Swap!

You can use most of what you have now for the swap (exhaust manifolds, driveshaft, etc.).
The only "special" parts you will need is a driver's side motor mount bracket (the ears on a 340 block are different from the 318) and possibly a radiator with a thicker core for more cooling capacity. The mount is available from Schumacher (engine-swaps.com).
Pulling the engine and trans as a unit is actually easier than pulling just the engine. Hope this helps.