Predator,
The new engines is the xp model. I would use the 053 pipe with a round header. As for the bottom end like someone already stated make sure the bottom end needle isnt to lean. And for the mid range needle whatever you do dont touch that needle or you will have worse problems than you have now. What kind of temps are you running in? I would try maybe putting a dyn#3 plug in it also. This plug will make the motor easier to tune.