I have an 86 with a 91 ho 302, street cam, 650 double pump holley, edelbrock performer intake, msd box and coil, stock dizzy, ford motorsport shorties, cylinders 1, 4, 6 ,7 are dead. What I mean by this is when plug wire is pulled of engine does not idle down. I put new plugs, and check the plug wires by grounding them to the body, i also check compression and its about 120 in ea cylinder. I spray starting fluid all around the intake to check for leaks and nothing. I also checked the push rods and they are fine, the rockers are not sloppy. and clues?