360 swap 1965 Barracuda

I might be wrong, but IMO the driveability and amount of cost of a crate 360 is going to be much better than building a 400+ 318. Before making any big engine decisions, I would price and plan everything out and pay particular attention to 1) how much compression you are dealing with and 2) how radical the cam is. Then make some hard decisions on exactly what you want to do with the car and how driveable and fuel efficient you want it to be.

When looking for a 8 3/4, there are lots of different options and other choices such as final wheel bolt circle diameters (4 vs. 4.5).

Also, with a 833, it is the clutch you have to worry about not holding up, not the tranny. Make sure to research this before you make any final decisions - it will also affect header choice.