2004 Ls1 GTO, I want to install 243 heads because I’ve read it will wake up the BTR stage 3 cam I have. I am wondering what all I need to go ahead and buy to complete the install, as well as, what do I need to have done to the 243 heads prior to installing? Trying to stay as budget friendly as...

I just rebuilt the ls2 in my gto. 44lbs injectors, Rebuilt heads, crank and a small cam. Last engine killed the cam and lifters. I got everything timed PERFECTLY. All connectors/ sensors are plugged in correctly. It cranks and wants to start once or twice then shuts off. If I hold the gas down...