building mt first turbo motor, a big-bore 347 with 240 high ports, super vic efi and a billet wheel BB midframe turbonetics with a 85mm f1-s turbine wheel and 1.14 a/r blowing through a 4150 throttle body. goal is a 750ish rwhp car i can drive around a couple times a month during the summer. my questions are how much rpm will this motor need (it is a tko 5sp) and header and crossover diameter, 1 5/8 to 2 1/2" or 1 3/4 to 3"? thanks john

 

To make 750 wheel horsepower I think that 1 5/8" turbo headers a 2 1/2" crossover will do the trick. I personally have quite a few friends here in town making over 800 wheel horsepower with a 347, pt76 turbo with 1 5/8" headers, 2 1/2" crossover & a 3 1/2" down pipe. With all the parts that you have, the power that you want to make should be easily obtainable with a good tune up

 

in my 02 cents them heads are a little over kill! id look for a head in the 200-210 intake runner.