blown1500

Break in on a flat tappet is critical!!
Spring pressure is critical and too much will wipe out any flat tappet cam in a hurry. Proper pre-lube of the cam is also critical. I also strongly recommend using GM EOS (Engine Oil Suppliment) available from any General Motors dealer-this helps more than you can imagine!!

Killer TA

Are you running duel valve springs. If so you need to break the cam in using only the outer springs.