The carb is a new 4160 with a plate (instructions said equal to 75 jets) and checked the air bleeds and all is clear. I put the 72 jets back in with the 35 power valve and the car ran pretty good but sputtering on the top end still. So I changed the mechanical advance to the red 28 degree bushing and set the intial to 12 degrees. Car started and ran good as usual just cruising around. Now when I mash the throttle the sputtering and popping through exhaust happens much earlier in the rpm range. Is this a symptom of the engine not getting enough fuel like was mentioned? I am going to try a buddies 750 double pumper or race demon carb to see if more fuel helps. Thanks for your help guys.