stock 516 heads and cam info please

Stock VC shouldn't be an issue as long as you're not running aftermarket rockers-if you are, test fit. Stock springs will probably float or bind with .500"+ lift I bet...I've only read about it personally, but I think anything over .480" with stock springs and such is not advisable. For that matter, I think the stock heads might require the guides to be cut down to allow for the higher lift and bigger springs...but I'm sure someone on here will chime in shortly with more accurate info.

MRL performance is a great source for general info...