[coyled]

Put the fel pro head gaskets on it for sure. I would find out if the block was decked and the heads were milled. A flat surface should eliminate any head gasket failure do to poor gaskets. Take a picture of the pistons and also keep the plugs. The tops of the pistons and the plugs for that matter, will usually show pitts if there was severe enough detonation to blow a head gasket. A magnifying glass will be needed to see the pits if there are any on the plugs. Once the motor is going again, I would take it to a rear wheel dyno that has an air/fuel ratio exhaust sensor. This will tell you if it is to lean and pinging. 12.8 to 1 or fatter should be safe, with 100 octane fuel . Also, check the timing. With lots of compression and good heads, it is not neccesary to run 38 total to gain the best power. Running less(32 to 35) timing will be easier on the motor and still make as much power. The builder may be telling you right now that the warranty is over. If the evidence shows that there was no pinging(plugs, pistons), maybe the builder will reimburse you for some or all of the repair bills with out getting into a legal battle which is almost always more time, money and trouble, than its worth. Good Luck, Scott.