MUKAK

if your heads are done/fixed please tell me how many miles you driven since.

Unreal

24k

MTPZ06

I assume you would also want to know if any periodic reinspections have been performed since the rebuild...and what those findings were?

As for mine...fixed by AHP late last year, less than 1K miles of driving since then. MS90 guides, Stock Ti intakes, Ferrea hollow stem exhaust, PSI 1511 springs, stock rockers/CHE trunion upgrade.

Vettes4life11

AHP heads 500 miles ago!

rio95

Bought 12k miles on mine and passed wiggle test about 1k miles ago. Can't say how long they'll last, but so far so good. WCCH, solid SS exhaust, btr dual springs, big cam, etc.

Lawdogg

WCCH stage 2 heads. SS exhaust valves. .660 lift cam, 25,000+ miles, 25+ track days, hundereds of 7000 rpm shifts. Replaced valve springs at about 20,000 miles as preventative maintenance. All was well.

redbird555

9k on mine so far fixed by ahp pm guides psi1511 springs

Unreal

Heads were reinspected at 22k and showed no signs of wear compared to 18k miles with valves 4-5x service limit and easy to move around in guide.

JoesC5

My "fixed" heads are new PRC265 heads with all new components(castings, valves, retainers, springs, locks, etc) and I have 24,700 miles on them.

Cordes Performance Racing

we have a c6z customer that daily drives theirs and beats the living crap out of it and has 48k miles on his wcch heads. Off the top of my head he has the most mileage of cars we have done the fix too. I only know his mileage because he was in yesterday for an oil change and I noted the mileage and planned on swapping springs again. we recommend on an aggressive cam every 25-30k miles is smart.

SSMOKE

My car had 10,000 miles on it when I had the heads replaced with WCCH Stage 2 heads (bronze guides, SS exhaust valves, stock intake valves, BTR springs) and a TORQUER 110 cam. It now has 17,300 miles. I WAS getting some smoke on start up so I sent an oil sample to BLACKSTONE. My report read in part "Copper looks good next to universal averages, so it doesn't look like the new bronze guides have worn excessively.) Also, it quit starting on start so as far as I know, I am good to go.

jp_tt_awd

12k miles on my Texas Speed rebuilt heads, bronze guides, solid stainless ex valves, prc 660 dual valve springs with a mild cam.

-jp

fueledpassion

WCCH Stage 2 heads installed last year ~ 8K miles so far. Still good to go.

LMBTom

About 10k/3 years on AI-fixed heads. SS exhaust, bronze guides, PSI 1511 springs. I need to do another wiggle test soon to see how it's holding up. If I find any issues, I'll likely switch to PM guides and stock exhaust valves.

ConfusedGarage

17K miles since heads were done (WCCH bronze/OEM exhaust/katech ti mo intakes), all at ~550rwhp. Track days, couple drag days, daily driver.

There was nothing wrong with my heads at 16,000 miles, all intake and exhaust were in spec although the intakes were close to the service limit.

fueledpassion

I thought hardness was just one of several concerns when designing head components. I thought the biggest case for a bronze guide was for its heat transfer characteristics, no?

That aside, just getting a set of concentric guides installed to begin with is probably enough for most cars to hold up in the long run although I agree that side loading will also be a very real concern down the road.

Undy

The best characteristic of "silicone" bronze is its inherent lubricity from the silicone content.

ConfusedGarage

I run OEM rockers and my guides were in spec with a Torquer 110 cam the first 7000 miles. While I have no idea of their measurements now, all sounds well after another 17,000 miles (track/drag/hwy runs and daily driving) with the same setup but bronze guides. At what point are folks seeing side loading as an issue?

fueledpassion

Not sure that people are at this point. It's just conventional wisdom that side loading is very possible with the flat tappet rockers. The simple physics would suggest it should happen eventually.