Stay with the stock HG and CR.

The main reason why the 3mm HG blows is because it puts the top layer of HG above the line of the piston when its at TDC, which puts it right in the line of fire when ignition occurs. Having any of the sealing part of the HG in line of fire when ignition occurs will weaken the HG over time and blow it. If you notice, the stock HG is low or thin enough to leave the sealing areas of the layers of HG below the piston line at TDC when ignition occurs and thats why it doesn't blow very often. You will see this when you bring a piston to TDC and it actually comes out of the bore a bit. This is my conclusion to blowing 3 3mm HG's myself. I have yet to blow the stock HG and I've been pushing it to around 780 whp for a while now.

 

okay so i will run a stock HG, should i change the valves or leave oem. being the head is off already anyone have problems with the oem. i know that the ap1s had bad exhaust springs and caused some to bend valves. also anyone running turbo cams or is it not worth the money?

 

i would just go ahead and change out the valves and springs if you already have them. i replaced my valves and springs with the Brian Crower polished race valves, dual valve springs, and Ti retainers which i recently heard tend to crack or chip. so i would just use the stainless steel ones.

 

Definitely build the head or you will drop a valve in time. The stock valves can't take the heat over time. Go with inconel exhaust/nitride coated intake valves and I recommend Supertech or Ferrea well over the Crower crap.