looking at some new heads for my 505 m4 in the tx19. getting rid of the procomps(115cc) and goin to a 119 chamber/thick gasket otta drop my compression to near 12 to 1 , maybe a tad more, but cheaper to run no less. i'm looking for a head with good velocity on the runners and somewhere around 390cfm at .700, the rhs 360 head looks good, but the port size leaves me thinking their gonna kill me below 6krpms. the dart 345cc look pretty good too and are a option. so what i'm getting at is what head between afr/dart/rhs would be a better choice for my say 12-12.4 to 1 505? wanna make the most hp at near 6300, let the nitrous carry the motor to 7k. getting chris to grind a cam for whatever head i decide on, so they need to be outta the box ready/good flowing heads. wanna keep the head upgrade to 2k or less, it was doin good on the procomps already, but i want less compression and a better head/cam combo , so what's lost in compression over the winter, will be made up with a better combo building hp at lower rpms let's hear some suggestions, are the 345cc darts to big? how bout the rhs 360cc heads?