Ok so I missed an auction... $481 was my bid.. vortec heads "906" which people say some have problems.. but these had pro comp springs, retainers, etc.. good to .510 lift cam.... plus intake.... anyway missed it.. the guy said the guy still hasnt paid him so I will know soon if he will sell them to me.... he legally or ebayilly had to wait till thursday... so im waiting... so if i get that there is no questions... now on the side note I found a set locally... vortec stock 1996 heads.. just asked what the casting number was... so since these are stock with 50k miles.... some say that those heads are good to .450 lift and some say .480 lift and some say .475 lift... anyone know for sure????? the cam I am looking at is .474 so the first auction would have been nice as I dont have anything to worry about... but these stockers.... if .450 is max..... cant get the xtreme 4x4 cam then... how hard would it be to get the heads to accept the .474 lift cam? I appologize for my ignorance on intelligence on this subject... If I cannot figure this out... im just going to drop the stockers on with a intake and leave the cam alone for now.... but if all it takes is z28 springs (what year) and lt4 retainers...... then Ill do it.... just hope the guy gets back to me with the first...... .510 would be plentyful.... also with a .474 lift cam I should be able to go 1.6 or 1.7 rollers in teh future huh?????