The LS7.R built by Katech that was in the GT1 racing Corvettes shared literally nothing with the street LS7.

Agreed. I’ve had really crappy experiences with a couple of “gold star world class shops”. I just wanted a tune. Apparently it’s not enough money for them. Still waiting for a quote months and years later. You can probably figure out who the two world class shops are.

 

Well, and I'm not trying to start an argument here, but IMHO, your statement isn't fair to the "gold star world class shops" that truly ARE world class. I think we all would appreciate knowing for sure just who you're referring to. This LS7 debacle has taught me a lot about cylinder heads. The two most important things I've learned are that,
#1: heads are similar to a chain in one respect; all it takes is one weak link to fail, and a $20,000 "chain" is junk, and,
#2: is that some LS7 heads are never going to long term reliable, for whatever reason. I've had Thomson Automotive (now LPE), AHP, and Tony Mamo all "fix" my heads. Thomson Automotive's work lasted 20 000 miles. 1 Ti intake was still good, and all 16 guides were shot. AHP's work went 30,000 miles before one of the 16 guides failed miserably, hence the weak link statement. The rest of their work was fine. But that one failure caused me to pull both heads, again!! How that valve didn't drop, I'll never know. I now have nearly 8,000 miles on Tony's "fix." So far, all is well. He did a great job. If I had to recommend one shop, I'd go with Tony. I'd also scrap the OEM LS7 heads, and go with his own proprietary TFS castings. His work is as good as, or BETTER than, anyone else's. But his customer service and communication are ABSOLUTELY BETTER than anyone else's in any type of business I have ever seen. My .02, but I'm not alone.

 

Grinder11 did you also get roller rockers recently to help with this guide issue?

 

YES! I talked at length with Tony about this. I went with YT rockers. Why? Mainly because rockers are THE ONLY THING I haven't changed, and tried, on the OEM heads. I felt it was worth a shot. 1 thing I found VERY interesting after installing them and checking the wipe (roller?) pattern was that the pattern was dead nuts in the middle of the stem! So why am I on my 3rd fix? The geometry appears fine. Are the rocker mounts flexing? I have trouble with that theory. Why, again? Because metal fatigues, and eventually breaks. The pedestals have lasted 10s of millions of cycles, and haven't broken. So.....Why the guide wear????

 

I had been looking forward to having Katech do the head work along with some other things on my C6Z this spring and just had what I consider to be an unusual experience with them.

I called their engine and vehicle department earlier in the week and a knowledgeable person answered the phone. I explained to him what I was looking to do - head fix (their Stage 1 Package) with some things added. I sent him a document detailing what I was looking for and they responded shortly with their answers, suggestions and recommendations. After 2 days of what I consider responsive / excellent back and forth communications, they provided a quote with a timeline, a detailed warranty document and stating they would require a 50% deposit to put finalize the order. Being ready to move forward, I asked for their bank information to wire the deposit.

I received an email with the final proposal, their banking information and an an extensive document releasing them from most responsibility with regard to the work. Most of the release was expected and reasonable, but I had questions regarding other items, specifically as to the vehicle not passing emissions testing. Being this is a street only vehicle and registered in NY this was / is important to me. I was confused as there were no emissions mods being done and the car is essentially bone stock (no headers exhaust, etc). I asked some questions regarding this, hoping to get to a point where I had some assurances the car would pass emissions, even explaining in NY there was no visual inspections or tailpipe testing, just an ODBII interface to confirm all emissions related sensors were present and online.

What I got in response to this question and explanation was very surprising, because their C6-Z06 Stage 1 package is specifically touted for mild street based vehicles.
"Katech does not imply or guarantee federal or state emissions compliance. Vehicles modified by Katech are intended for off-road use only, and any modifications made to vehicles in emissions-regulated states are done at the owner’s discretion. Based on the concerns discussed, we do not feel this project would be the best fit for us to take on at this time".

 

Wow that's a corporate response if I have ever seen one 😬

https://americanheritageperformance.com/

 

Yeah, I was pretty surprised at their response, I was expecting something along the lines like of "we can't guarantee emissions passage, but are not making any emissions changes and have done XX Stage 1 cars from NY and none have had problems passing NY emissions". I was looking for some assurances that I was not going to end up with a car that couldn't pass.

The planned work included heads plus rear main seal, clutch and flywheel. I want one shop do everything (disassembly, reassembly and machine work). 10 years ago I would have disassembled / reassembled myself and sent the heads out to get fixed, but those days are over for me.

Katech was a great option, because they are only 650 miles from me, I was going to trailer the car out, leave leave my trailer and car there and then trailer it back home when done.

Lingenfelter was my backup to get this work done, because they would also do it all, but based on the information earlier in this post they don't look like a good option these days.

 

I have to honestly say I didn't think I'd EVER hear anyone say that Lingenfelter is no longer a viable option. I'll bet John Lingenfelter is turning over in his grave like a rotisserie!! He built LPE on C4's, C5's, Firebird's, and Camaro's. SMH...HARD!!!

 

The intake and tune in their stage 1 package technically affect federal and some states emissions compliance, so they have to have that legal disclaimer to protect their business. The car might well have passed inspection, but they can't reasonably be on the hook to promise that.

 

When I had Katech install their stage 2 several years ago, I don't believe they would install headers unless it was for off-road use.

 

A lot of shops are scared of getting in trouble/fined, which as a shop owner I totally get.
With that said, I hate that the gov thinks it can tell us what to do with our cars and our money so I for one as an owner do not subscribe, lol.
You still have to use discretion though... These agencies do use secret shoppers to try to catch shops doing stuff like installing headers, tunes, etc... Glad the gov has nothing better to do than catch honest folks modifying cars haha.

https://americanheritageperformance.com/

 

UPDATE on my post above. I have decided to move forward with Katech’s proposal. As mentioned by others here, this is a difficult time for shops working on modern emission controlled vehicles. Considering that in my case, KT will not be making any modifications or changes to the emissions system, I think all will be good.

 

I never said it did.