291c head question

[hohner0006]

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!!

[jeepsr4ever]

Your entering that grey area where you could run out of slot if your rocker has funky geometry or you have it higher/lower on the stud. I would do a mockup first and then decide if you need guideplates and have to open the slots. The main advantage to guideplates besides holding the pushrod is they hold it higher closer to where it should be and that has a definite mechanical leverage advantage over slots in the heads. Whether or not you will see this mud racing is hard to say (probly not with that lift cam)

[hohner0006]

If I chose to run the guideplates (and open up the slots) is it necessary to remove material from the rocker stud bosses to accomodate the thickness of the plate?

[jeepsr4ever]

Not unless those are VERY thick guideplates.