it hapenned to me to.... when I turbo my 6M withoiut changing to MHG.... it runa pretty good and no lean at all on the AF gauge.... 3 bars green and no detonation or ping at all during boost... I ran it at 6 psi... but as soon as I did a one pass at the track... and making the car work hard at the 1/4 mile... with just a open 3" DP... at the end of the track... booom an blown headgasket and a show forthe crowd.... found 5 spots on the headgasket blown.... I wich I still have the blown gasket for memories
now the 6M is built and hoping to make 400+.... hopefully w/ the shot peened and polished 7M rods and ARP rod bolts, main studs, head studs... and also the 2.0mm HKS Bead MHG... and the most important the 8.0:1 Ross Forged Racing pistons and rings