valvetrain problems

Honestly, going through the trouble of changing the cam and leaving the stock heads on is pointless. At the very least, you could get the e7 heads ported, or pick up some cheap iron heads.

If you don't have the budget, though, I belive Comp. Cams has a kit with the 'Cobra' valvetrain, rockers (1.7 ratio) and I am sure you can get the lifters, push rods etc.
COMP Cams - Performance Camshafts, Valve Train, & Much More Just make sure you get the right firing order if you buy a cam.