I got a friend who owns a 2000 si. He blew his block and replaced it with a 98 gsr block with some internals. Ctr pistons were placed on the gsr rods and itr cam shafts were used. His only other mods are cai and aem cam gears. After breaking the motor in, the cam gears were tuned to +4 intake and -2 exhaust. The car was running very strong but after a week the idle was low. The car would cut off when the rpm was low. We also noticed that the engine was smoking. Once we open the valve cover smoke was coming out. We took the engine apart and noticed #3 and #4 pistons were cracked as well as the head gasket broken. Everything was replaced as before with an addition of 4227 Bosch Platinum plugs. The cam gear are also set at 0 0 now. I was wondering what went wrong and what should he tune the cam gears at. tanks