Head Fix - Keep your own or core exchange
Thread Starter
Instructor
Joined: Oct 2024
Posts: 204
Likes: 68
From: South East MA
Head Fix - Keep your own or core exchange
I'm gearing up for the head fix on my car and most shops are pushing a core exchange so they can take the car in and get it out the door faster. Aside form the obvious benefit of very little downtime, I'm not sure I want to do this. My main thinking in reading some of the posts here is that some heads are just damned no matter what you do to them and how many times you have them machined. On the flip side, if you have a set that could be good for higher mileage, you'd probably want to keep them not to mention there is some merit to wanting the heads that your car was built with. Am I over-thinking this? Looking for feedback from others who have been down this rathole.
Melting Slicks
Joined: Apr 2019
Posts: 2,518
Likes: 1,168
From: Northern Wisconsin
I had the same thoughts when I had my heads done. I decided to go with the exchange process with AHP. No regrets. I would do it that way again. I just can't justify having the car down that long when re-doing your original heads.
Burning Brakes
Joined: Nov 2011
Posts: 862
Likes: 78
You could always look into aftermarket castings which are superior anyways. Probably more money but you'll have no valve drop worries. Brodix, Trickflow, PRC, Frankenstein, Mast Motorsports etc. And you could sell your current set to somebody else as cores.
Le Mans Master
Joined: Oct 2007
Posts: 7,456
Likes: 977
From: RI, Now Franklin/Nashville TN
I am the original owner of a very low mileage C6Z06 (8,400 miles, currently) and when I was considering the "head fix" a few years ago, I was of the same thought process as you, wanting MY OEM heads rebuilt, not willing to do an exchange. As you stated, you really have no idea what you are getting with an unknown "fixed" heads from other cylinder head cores: how many miles on them, how many heat cycles, what kind of other stresses, were they previously worked on or not, etc?
I have since decided 2 things more recently:
1. Because of my extremely low mileage LS7 engine and how I run and maintain the engine, I have recently removed the OEM LS7 GM slider rockers and replaced them with Yella Terra 1.8 OEM direct GM replacement aluminum roller tipped dual pedestal rockers, for cheap insurance, on my totally stock LS7 engine. I will check the the valve guide play at 10,000 miles, since currently they are showing zero play.
2. Since "fixed" heads can and do fail at all sorts of mileage, both low and high, mostly on Z06's with modified engines or those that are raced, when or if I decide the heads should be addressed, as noted above by others, I for sure, will go NEW aftermarket LS7 replacement heads since the failure rate is almost non existent from the new aftermarket heads.
I have since decided 2 things more recently:
1. Because of my extremely low mileage LS7 engine and how I run and maintain the engine, I have recently removed the OEM LS7 GM slider rockers and replaced them with Yella Terra 1.8 OEM direct GM replacement aluminum roller tipped dual pedestal rockers, for cheap insurance, on my totally stock LS7 engine. I will check the the valve guide play at 10,000 miles, since currently they are showing zero play.
2. Since "fixed" heads can and do fail at all sorts of mileage, both low and high, mostly on Z06's with modified engines or those that are raced, when or if I decide the heads should be addressed, as noted above by others, I for sure, will go NEW aftermarket LS7 replacement heads since the failure rate is almost non existent from the new aftermarket heads.
Last edited by jb78L-82; Today at 05:50 AM.
Supporting Vendor
Joined: Sep 2013
Posts: 3,102
Likes: 1,271
From: Harbor City California
If your goal is less downtime, there's nothing wrong with using a core set of heads, especially if the vendor has high ethics when it comes to cores. For example, we only keep the best-quality cores that we rework from. If we get a set of heads that doesn't meet our quality standards, we actually sell them to other shops & wholesalers. In short, we're extremely picky about the cores that we accept. If you get cores from us you can be assured they are of the highest quality.
https://americanheritageperformance.com/
https://americanheritageperformance.com/
Pro
Joined: Apr 2016
Posts: 604
Likes: 246
From: Indiana
This would be my choice if fixing heads. I’d call Tony Mamo and get a set of his aftermarket units and either sell the stock heads to offset the cost some, or stick them on a shelf if you don’t wish to part with them. If/when my fixed heads need refreshed, this will be my course of action.
Supporting Vendor
Joined: Sep 2013
Posts: 3,102
Likes: 1,271
From: Harbor City California
Just throwing this out there...
If you want Aftermarket Castings, you can go with our Archangel LS7 Heads, which are based on the very robust Brodix BR7 Castings.
They are the same heads that power the worlds fastest n/a 427ci C6z06!
You can read more about it here:
https://www.corvetteforum.com/forums...ord-again.html
https://americanheritageperformance.com/
If you want Aftermarket Castings, you can go with our Archangel LS7 Heads, which are based on the very robust Brodix BR7 Castings.
They are the same heads that power the worlds fastest n/a 427ci C6z06!
You can read more about it here:
https://www.corvetteforum.com/forums...ord-again.html
https://americanheritageperformance.com/
Burning Brakes
Joined: Apr 2016
Posts: 1,121
Likes: 110
From: Chattanooga TN
Just throwing this out there...
If you want Aftermarket Castings, you can go with our Archangel LS7 Heads, which are based on the very robust Brodix BR7 Castings.
They are the same heads that power the worlds fastest n/a 427ci C6z06!
You can read more about it here:
https://www.corvetteforum.com/forums...ord-again.html
https://americanheritageperformance.com/
If you want Aftermarket Castings, you can go with our Archangel LS7 Heads, which are based on the very robust Brodix BR7 Castings.
They are the same heads that power the worlds fastest n/a 427ci C6z06!
You can read more about it here:
https://www.corvetteforum.com/forums...ord-again.html
https://americanheritageperformance.com/
Do y'all accept cores that have already been worked by someone else previously, as a core?
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Supporting Vendor
Joined: Sep 2013
Posts: 3,102
Likes: 1,271
From: Harbor City California
- They'll sink a valve job and leave a nasty lip where the seat meets the chamber.
- They'll use oversized guides, which distorts the guide bore and often times doesn't give it the correct press
- They'll crack guide bosses.
https://americanheritageperformance.com/
Melting Slicks
Joined: Dec 2017
Posts: 2,010
Likes: 918
From: Baie-D'Urfe, Quebec
2023 Corvette of the Year Finalist - Unmodified
2022 C6 of the Year Winner - Unmodified
I did the core exchange with AHP 9yrs and 30,000km ago (about 15% track, but with temps managed).
I trusted them on their reputation, feedback and that their inspection, machining and the geometry would be fine.
Down time was 2 days at my local Porsche indy shop and I do still send Kohle my Blackstone results just so he can see how things are holding up.
Frankly though, I'd have considered aftermarket heads if I was doing power adding mods that would affect geometry, pressures, etc....but stockish hp is enough for me on track.
Having become accustomed to some LS7 quirks, I suspect some longevity issues may have to do with owner issues, temps, lubrication etc...but thats just my opinion.
YMMV
I trusted them on their reputation, feedback and that their inspection, machining and the geometry would be fine.
Down time was 2 days at my local Porsche indy shop and I do still send Kohle my Blackstone results just so he can see how things are holding up.
Frankly though, I'd have considered aftermarket heads if I was doing power adding mods that would affect geometry, pressures, etc....but stockish hp is enough for me on track.
Having become accustomed to some LS7 quirks, I suspect some longevity issues may have to do with owner issues, temps, lubrication etc...but thats just my opinion.
YMMV