Roush heads vs. GT-40p?

[james t]

ok, here's the deal. i can get a set of brand-new, unused Roush 200 (World Products Windsor Sr.) heads for $500 from a friend. they list in Summit for $800. ive got a set of GT-40p's that i got off of a boneyard X for $150. i have another friend who is gonna port, install bigger valves, run on the flowbench, etc. when he gets a chance. kind of backed up with business right now, so it may take him a while. the Roush heads have 202 an 180-something valves, big chambers, and flow real well right out of the box. my stang buddies say the stock Roush heads are gonna be a little better than moded p's, but no one has experince with them and this is all just rumor. the bigger combustion chambers will drop my compression a little, but thats actually a plus. when i get the charger, i will ultimately be able to run more boost/safer. so, what do you guys think? i could buy the Roush's, sell my GT-40p's for $150, sell my stock GT-40's for $150, and wind up with $350 total in my new heads. all opinions welcome...

 

[mrboyle]

If you are planning on running a supercharger, the lower compression of the Roush heads are the way to go, but what you need to do is determine weither the Roush heads flow too much air for your application. It is true that the biggest gains in horse power are made by increasing air flow, but if you increase it too much it will have a negative effect on the engine's efficiency. Your best bet is to talk to a professional race engine builder and get their opinnion. He will want to know specifics, like cam lift and duration, injector size, TB and MAS size, header primary and collector size and what type of supercharger you plan to run. All these varriables will effect the way the engine responds to modification.