geezel

Going to freshen up the heads on my street driven 30,000 mile 2007 Z06. Should I go with bronze guides (e.g. WCCH Stg 2 Pkg) or PM guides (e.g. AH Stg 4 Pkg)?

MTPZ06

I went with AHP...but upgraded to their MoldStar 90 guide material. I wanted the best available...

Here's the testing data AHP did on numerous types of guides...nothing speaks more than numbers.

outhouse

AHP is your best bet, I used them and my heads are there now.


Nothing but positive reviews.


Their powdered metal are there own recipe and better then wcch bronze

got2hav1

Did AHP #4 since I kept the stock cam I used their PM guides. Had I gone with a hotter cam I think I would have upgraded like MTPZ06. I did go with the Ferrea exhaust valve. Valvetrain is very quiet now and I am happy.

geezel

OK. AHP it is. What do you guys think about the PAC 1515ML beehives -vs- the BT duals that AHP offers? From the BTR website: PSI 1515ML .650" Lift Beehive Springs. Designed for LS7 and other 1.950" installed height applications. 140 lbs @ 1.950", 405 lbs @ 1.300", Coil Bind 1.225", 1.290" OD, .630" ID I will also ask AHP about those...

MTPZ06

Stock cam? I had AHP do the 1511 beehives with Ti retainers...I'm still on the stock cam. I believe the consensus is that the 1515 spring is a bit robust for the stock cam, but certainly an excellent choice if going to a more aggressive cam. I believe (very recently) BTR now makes Ti retainers for the 1515 springs.

geezel

Yes - Stock cam. I'll go with whatever AHP suggests.

MTPZ06

Kohle likes the BTR duals, Katech likes the 1511's. Me personally, I wanted an OE style (but better) beehive spring, thus the 1511's were my choice. Stock cam, I really don't think you can go wrong either way.

outhouse

That's exactly what I did. I normally make good mechanical decisions on my own, but these guys are the corvette pro's as far as I'm concerned. No reason to second guess their choice.

vertC6

ONLY use the PSI 1511!

geezel

Obviously the 1511's are good for the heavier exhaust valves?

MTPZ06

With stock cam (and some aftermarket ones); the combined mass of using the combo of Ferrea f2042p hollow stem exhaust valves (that Kohle uses), 1511 beehives, plus Ti retainers, plus stock rockers has been tested/proven to be a good combo. That's precisely what I went with...along with Kohle's MS90 guides and a CHE trunion upgrade.

redbird555

I have ahp heads non ported though with the stock cam and 1511s with tI retainers and on guides. Very happy if you actually do the math you lose about 1lb of valvetrain mass going with the 1511 and ti stuff. Even stick sorings with the 2024 valve which is all standard with ahp has been tested stable to 8k rpm

geezel

Thanks for all the replies.