How much HP and what do you think it will run.

I forgot to add I haven’t decided on gearing and torque converter so if you could give me some suggestions I would very much appreciate it. Thanks
It's going on a Dyno correct?
If so you'll have your data. You'll need to be looking at your peak torque numbers rpm and weight of car. The horsepower and weight can get you sorta close on a calculator. Then just make up your mind on which rpm you want to cross at and what your shift points need to be.
Chances are better 4.10-4.56.