Thier will be enough space for the engine, Im not sure about fitment with these headers though. For reference My 242 ls with performance bravo one and 509 c.i. is currently at 68 mph on gps with a 23p standard mirage (non plus) at 5200 rpms. The motor on the dyno made 470 hp and 550 ft lbs of torque. The motor originally made 525 but the builder ended up putting in a smaller cam on rebuild. I should see 70-72 when I get the proping figured out/ tweaked, and maybe a -2 shorty.