Need some input

[banshee1856]

Just got my bike put back together after it seized up. Before I had only DMC 916 exhaust, v-force reeds and k&N filters on it. Now it has a +4 mill stroke, 65 mill long rod pistons, shaved the head .030. The bike starts up very well and easily and will idle with no trouble, but as soon as you open the throttle it starts gasping for air. Before the rebuild it was running with 320 mains in it and the needle was at the second to top position if I remember right, and it ran like a bat outta hell. We have changed the mains from 320 to 310 to 280 even to 230 and moved the needle in all different positions. We have cleaned up the carbs and checked and rechecked everything we can think of but it just wont rev up. The plugs were totally black when we pulled them and the exhaust never gets hot. I can sit my hand the pipes the whole time its on and they only get warm but never hot which leads me to think it is too rich but going all the way down to 230 mains and seeing almost no difference from a 320 has got us stumped. No matter what we have done the there seems to be no change in the way the bike acts whether we have it rich or lean as we can go. Has anyone had a problem similar to this or have any ideas on why it would act like this?