So I finally got my custom carb back and now the car cuts out on me at around 4000. Its fine in neutral but with an actually load its another story. I had the car dynoed before the carb work and it ran up to 5000 just fine, but a short time after words I raced the car without the supercharger hooked up and it sputtered a little at top end but I thought it was due to having a supercharger carb tune on an NA engine since the blower was unhooked. Well now the carb has been pro tuned for my application and the supercharger is running, but now its worse. I checked the plugs and they are clean with a slight discoloring of the white which I believe is normal. There is no oil and hardly any gas fumes on them. I've tried different jetting in the rear too from 83s,86s, and 90s. I assume this would cover the range of lean and rich but no change with whatever I do. I found one cracked plug wire from header heat and I changed it, again no change. I have no vacuum leaks, no fuel leaks and Im stumped. Is it a fuel thing or an ignition thing. I'm using an MSD 6al, msd coil, MSD pro billet, and MSD wires with autolite plugs. What gap should I use with aluminum heads and 12 lb supercharger? Thanks, let me know if I forgot something or if you need more to go on.