Hi Scotty. I have a 75 Ford e350 with a 460 with a Holley 650 double pumper and all my vacuum lines are good. The jetting is too rich but no deposits on the plugs and my whole passenger side bank leaks exhaust at the manifold with enough flow to allow a small air craft to take flight. My idle is rough and doesn't smooth out until alittle over 1300 rpm. Could the known conditions cause this?

heck, I hate holleys, I would throw that away and put on a brand new edelbrock, I do that all the time on those.. New universal ones work fine and cost little on the net

Atleast I wasn't the one who put it on lol. It's a 22 ft RV I bought a month ago replacing odds and ends. Once it's driving though for 8000 pounds it will lift the front up with torque