okay guys heres my problem valve ping at part throttle about 2000 rpm. now here's what I have 79 f150 351m edelbrock 600 carb edelbrock performer 400 intake stock manifolds 2in pipes thrush glasspacks. carb is set up with 104 jets and 73 x 47 rods on the primary and 98 jets on secondary. distributor set at 10 degrees initial with vac advance hooked to ported vac on carb.on edebrocks calibration chart have tried 1 9 and curently on 15 have also tried grades 87 89 92 and 94 on gas also to no avail. if babied on acceleration will not ping if stomped to the floor will only ping at around 2000 rpm . asked my dad the same question his response " If Ford wanted a 4 barrel carb on they would have done it at the factory" so if you you guys have any suggestions I'm all ears or eyes rather. thanks in advance for your most excellent help.

mike