I know there is alot of jetting questions in this forum, but i need to ask one more? My 450 "craps out" at high RPMS, its got a snork, modified exhaust, K&N, etc..., I installed a oem 136 main. It pulls hard low and mid range , but when the RPMS get up it acts like its hitting the rev limiter, but pre-maturely, mabe its starving for fuel? Is there a tunning trick i dont know about? I mean, if it was a holley, piece of cake, but this little terd is very touchy! do they have a power valve?