I know since ive joined the forum ive been full of question but i have searched everywhere and cant find the answer. Ive got a set of edelbrock performer aluminum heads on my 87 mustang and i was wondering how high i can rev the motor before the valve springs give? The model number on the heads is 60379. They are 1.90"Int/1.60"Exh. I bought these heads when my bottom end was still stock and i could go with anything better because of the piston clearance so they will have to do for now. Can i rev to 7500+ with these head stock or can i do something to them to allow for it?

 

Unless you have a solid roller lifter setup and valvetrain components to match, no. These look to have single springs, not the thing to have when trying to maintain valvetrain control at higher rpms. If you're running a stock block along with that blower setup and trying to rev it to 7500 rpm, you stand a pretty good chance of splitting the block, never mind the forged rotating assembly inside it.
IMO, it's better to build a new combo "from the ground up" that can live a long(er) life under the conditions it will be subjected to. Would probably be "cheaper" in the long run (though it never really is ).

 

I had a feeling the valve springs would like to see those kind of rpm's. Yea my block is only a 2 bolt main right now. Im just trying to figure out what i can use and what i cant before i start the new wish list. Lol..... What I want to do us get a 4 bolt, a set of AFR 225's and get a custom cam made but the finances dont allow for it yet.