Excaliber Ernie 12.5 is not all that bad for a street motor with octane boost. You have turbo motors on boost that make a high compression. If you can go Hydros, Great!! Too much Lash was the start of the problem, Make sure the cam matches the motor. Springs too for the valves. I just got Dyno sim, what alot of setups for my next motor. You could put TWM with FI on the car and pickup 20-40 hp in the mid range. What exhaust is on the car? Getting the right back pressure could be worth 20-30 hp. You are half way back to you orginial 600+hp. Flywheel steel or Alum? 20lb alum will let the motor spin up faster. Pushrods are maybe chromemoly tubing or something of that strenght. Give the 7G shifts up. If the cam is done at 6K then put a 6500 chip in the box and save the motor. Just a Thought
Rick Lake