With those heads I'm surprised you got it to wind up in 2nd. The nosing over is the heads. Terry Rosebush on Ebay is selling the old style Dart heads for 399.00 a pair bare. They are a good buy. I got a set for a friend, put a good valve job in them and swapped all his stuff over. That along with an intake swap picked him up a second in the quarter. A 200cc head will be good on there and if you think you might ever want to go faster, 215cc would be better.