Dave i bought this engine the block is a old ls7 block, i run a single dominator, 14 to 1, on gas, had copper head gaskets on it with copper coat, i just pulled the heads & sent them to hrd head service to have them ported & looked like 1 chamber had some water, Curtis i don't want to deck the block i would like to be able to pull the ss o rings out of the block but have had no luck removing them, worst case i will use the copper head gaskets & silicone around the water jackets? thanks for the help Doug