Is a aluminum head with dual OHC......as for the head gasket not sure the reman head was put on about a year ago at the shop and it blew I guess a while back and customer sent it to shop to have new head gasket put on. The customer does their own " maintenance".....using that word LOOSELY....and noticed coolant in the oil I guess....after they received truck back it had this miss AGAIN......this has an IMPCO Model J reg that I installed in Feb 2012 and a VFF30 Lockoff....I'm thinking th model j is giving it fits as the ones we have been getting are crap,am leaning toward installing a COBRA as that is what I have been installing more of and hold up better. Forgot to mention also that about a year and a half ago the timing belt broke and I installed a new one....was jut curious if this is a interference engine and maybe a bad valve? Would think the shop would of caught it tho when they installed the reman head....... The distributor is a electronic pick up with a regular coil with external resistor(all of which has been replaced with in the last year....but STILL this miss hesitate keeps coming back.........