I bought a set of 291c heads that were ported and polished by Traco and I have a couple of questions....I'm running a bit less than a .600 lift solid cam with Indy aluminum rockers and I'm concerned whether the pushrods have enough room to operate without contacting the top/bottom of the slots. If I'm going to open them up, now is the time (not installed). Also, is there any advantage in using guideplates with this series head? Anything else I should consider before I put them on the motor? Thanks in advance!!