Guess ET for 318 ? With slicks ???

I did not see a mention of any headers being on the car? headers and exhaust will free up some extra ponys.

And to be honest I think you are over carbing that 318 with a 750 unless you have it jetted way down.....correct me if i am wrong but stock they came with just over a 500cfm carb.

I think a good 600cfm is well suited for a 318 easy enough....then again I think a 670 holley street avenger would turn a 318 on great aswell.

I think the 4.56 gears would for sure get you a good jump out of the hole but not sure how far you can top out with it and without knowing if your internals are stock or not....you wont want to run at high rpms for very long on stock or mostly stock 318 unless you have no problem with walking home of course lol

good luck either way