What caused the head gasket to go on your truck? i was following your build thread for a while and remembered you not wanting to mess with a tune, did it have anything to do with the COBB? ive been sketching myself out reading about peoples experiences with the tune and been considering removing it from the truck
I had swapped the overflow tank to an aluminum tank from mishimoto. Last summer, heading into Bay of L.A., the ambient was 128 degrees. One of the hoses popped off the overflow tank ( because it is a crap design), All of the coolant squirted out of the cooling system within 50 yards. ECT hit north of 265 degrees and truck went into thermal shut down.
Unfortunately, I didn't have the ability to sit there for 8 hours until it cooled down naturally, so I had to dump cooler water into the overflow and radiator after reattaching the overflow hose.
Since then the head gasket has been failing slowly and I've put the factory overflow tank back on. ( and smashed the Mishimoto tank with a BFH.)
I was going to do a V8 swap, but no one will sell me the parts to make it easy. All of the companies that do V8 swaps will only sell the parts installed. Therefore, I'm going to do the head gasket, make a few other motor changes for reliability, then have it professionally tuned. I may revisit the V8 swap in the future once it becomes more DIY friendly.
I haven't re-loaded the cobb tune or trans programming since the truck began consuming coolant as to not compound the issue.
If it were me or if you plan to use your truck as I do, I'd recommend getting the truck tuned by a pro. Id also opt to retain the octane adjustment feature, as it would be a real pain to constantly reload tunes based on what octane the fuel is that you come across in remote parts of Baja.