Originally Posted by G8Pumpkin

Not an expert by any means on a z06 as I have only owned mine for 6 weeks bought 2011 used 21,000mi. Personally not convinced on the later models of the valve issue but I have put in the comp cam trunion upgrade after further digging and if I was doing it again would probably go with Staub engineering upgrade instead and no I do not live in fear of a valve failure. Have had it tuned by a local LS HP tuner and it goes like a missile now. Hate the run flats but there is no supply currently for Continentals in 19/20 sizes have them on order and probably wont get them until next year now. Had an alignment done it was very close to stock specs tramlined badly went with Pfadt street specs and it is a vast improvement. still hunting down one last issue which is a slight variance in idle speed it hunts up and down 200 rpm shows as a vibration at 60 in 4th as you are just barely on the throttle, I will find a solution to this problem. My tuner explained something interesting there are only 2 ignition timing tables so if the knock sensors pick up any knock at all it retards the timing and it not a proportional thing its one or the other and if you read the manual for a z06 it says 93 octane, so on regular premium or less you will find it doesnt run very good as it will knock the timing back so in theory it can run on 87 so 93 it is for me. Bang for the buck mine puts a smile on my face every time I drive it. PS it only says premium on the fuel door but doesnt specify the octane.

Originally Posted by MTPZ06

Valve guides affect all LS7's (C6Z, 427 Vert's, Camaro Z/28).

Just Goggle Comp trunion failure. Here's what will eventually happen to your Comp trunion bearings:

Originally Posted by G8Pumpkin

looking at this picture what I see is somebody doing a poor installation as that is the only explanation for there to possibly be score marks on the bottom of the trunion where it seats into the saddle. To me it looks like the cam was in the wrong position when the bolt was torqued and consequently it was the wrong torque which would eventually lead to terminal failure. As to the google search as it says about 1 failure in 1.5 million bearings doesnt seem to be a major case. When I was doing the install there are several places where install mistakes can easily be made, pressing the bearings in too far so they scrap on the inside of the trunnion, not checking every bearing that it is dead smooth before installing, I had to clean 1, somebody not following the install procedure exactly for torqing them down, not using the correct tools to install the snap rings, so as I said in my post I dont live in fear of them failing but I am very fussy on installs and do my own work for those reasons.