.......I didn't have a specific hp goal in mind but I would like to build the strongest street engine that I can while keeping the rpm under 6000-6200.
I like the OP's plans..... 512/ TF 240's/ TF intake.
Add some Comp Ultra-Pro Magum rockers, a nice solid lifter cam, QFT Q-950 type carb...... You'd be good to go.
The low deck TG manifold has the inner 4 runners really pinched down where they cast for the bolt reliefs....... Not good.
The TF piece is just better.
I've messed with the 4500/750's a few times.
Those were basically made to satisfy the "pro street" show crowd by giving them a 4500 carb to run on their 450hp street motors.
It would need new boosters and metering blocks to work properly on a 650+hp 512.
IMO, better off selling it to someone who can use it as-is, and put that $$$ towards a new carb.