mopar performance distributor recurve kit

I'm having trouble fine tuning my motor. 400 bored .040 over, shaved heads, 224/230 duration with 477/480 lift comp xe cam. 750 cfm carb on a dual plain intake. Recently upgraded to 3/8 fuel system and added a recurve kit in the distributor. Total timing set to approximately 37 degrees. Runs great when it reaches working temp. but runs like crap until then. This time of year it sometimes takes a while to reach working temp (very annoying). It did get worse when added recurve kit, but when warmed up, it definately made an improvement.