if you are running the stock intake and heads I would say 4800-5000 tops , if you have a PI head or even just a PI intake your powerband in the upper Rpms would be alot better and you could carry it out to 5200-5400 possibly more range ...... IMO .... if you dont have this and you car has a stock NPI motor get it , its one of the best mods to a NPI motor you can do (http://www.livernoismotorsports.com/product.phtml?p=457) ... and if you want a little more get a set of PI cams used with low miles and swap them on your heads too