Correcto! While it's true that you need to match components, I've read more than one engine expert that has maintained you can make better power with good heads and moderate cam than you can with poor heads and a big cam. Lots of guys have gone REAL fast with 5.0's with better heads and the stock cam. 5.8 heads are even bigger of a bottleneck than 5.0 heads because of the increased cubes relative to head flow. However, considering the stock 5.8 cam is REAL lo-po, a decent relatively inexpensive hydraulic flat tappet would get you quite a bit of what a full roller setup would, and should still let you get some decent heads. Ford has some real decent street cams for little $ - check
www.oemfordparts.com, their svo section. The Nov issue of 5.0 Mustang & Super Fords has an 11 head comparo article - you can get some really decent aftermarket alum street heads for around a G, and the Ford GT-40X heads for less which are still quite good - you don't want to go hi buck exotic unless you're going racing. The new AFR 185 came out on top by a little for 351 size motors and had a good, wide torque band.If you can't find the article and want to read it, email me and I can scan and send it to you. macx@clas.net