You guys mentioned the reason to use the thick gasket over the thin carb gasket when I asked which is better. Said it was to keep it from perculating. could you tell me what the symptoms of this is. I think I had that problem yesterday. Was coming back from the car show and the Duster ran like ****. I was going kinda slow to allow junior to keep up. I kept the throttle at a constant point, about 45MPH and I noticed it surging a little. I came up on a stop sign and I had to set the line lock and keep my foot on the gas a little to keep it running. later down the road, I pulled into a parking lot and it died on me. started it up and took off and put my foot in it and it seemed to clear up a little but have not had time to play with it yet. It seems to do this a little when hot, not cold. I also question whether it would be better to put a 650 Thunder series on this instead of the 750 I have on it now. I have a 440 .030 over with Kieth Black flat tops in it and a purple cam in it. 509/292cam. what do you guys think. I am leaning towards a thicker gasket. AM I PERCULATING. thanks,Bill