I think it will take a 90 mm throttle body to produce 450 hp with 408 cubic inches.
You need to match you air filter, air filter tube, mass air, throttle body, intake, heads, cam and exhaust system to produce max hp. Any one item can kill a lot of hp. Money wasted on good parts.
Lone Star Cobra 354 ci (3.47" x 4.03" 302 motor) EFI 402 rwhp & 416 rwtq with 37,000 miles, Custom Painted 06 Mustang & RCR GT 40, 302 with Eight Stack Injection system