My current set up on my ported 421. Aggressive port by HJR. 35 pwks, 152 main, 45 pilot, cel needle on 4th clip from the top. I have 19 cc domes, VF3 reeds and +7 timing. I started out with a 160 main and a 52 pilot and it did not run clean. It was clearly running rich and running hot. Make sure your carbs are synced and opening all the way. Check your intake boots and make sure there not cracked or have loose clamps. Check all the little stuff. I had my dyno tuned at Redline racing and It has ran great.