Depending on your camshaft you may need to take some of the spread out of your mechanical advance(welding up part of the slot and then fileing the slot so its a little smaller than before)I think I took 1/16" out of mine and it runs and idles like a champ. then you can get your timing where you need it and your car will idle properly without having the throttle blades open so far, and it should help with the dieseling.