just order the gasket from Nissan they really arnt that expensive!!! and it will blow agian if you dont work out whats going on, i mean who is to say that when the plugs been threaded metal shavings have gone into the cylinder and stuffed up the bore, gasket and pistons!
You said you have a SAFC 2 tuned on there and making 220hp mabe the tune on that is shit and detonating its head off? what fuel are you putting in it 98? what is the SAFC tuned for?
seems odd seing i made 256hp with stock computer, stock side mount just a pod and 3" exhaust on 9psi?