to make sure you have the valve relefs are ok this is a old trick put a thin layer of clay about 1/4 of a in then put the head on with some bolts just hand thght with no head gasket put on one set rocker arms with the pushrods set them at 18 lbs then rotate the motor 2 times slow take the head back off see how far the valve and piston cleared by how thin the clay is you need at lest .090 or you can e-mail me at
[email protected] with your phone #
65 GTO 455 525HP
69 GTO mantching #s all the way