Try putting a NGK plug number ending in -6,-7 and a -8 I blew out a Fel Pro PT head gasket, melted the 440 block and a M.W. iron head betwween the cylinders on #4 and #6 by swappping from a NGK-7 plug to a -6 at the track
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
I blew out a Fel Pro PT head gasket, melted the 440 block and a M.W. iron head betwween the cylinders on #4 and #6 by swappping from a NGK-7 plug to a -6 at the track 
