I honestly don't know man. Here's the story.
One 50* Friday night at the track I ran my PB of [email protected]
while spinning. Heard a little detonation so called it a night and drove home.
Called a friend up with a exact copy of my truck and told him how much fun I had. Changed the plugs during the week and don't so much signs f detonation. We decided to go the following Friday. It was 40* this night. I added 5 gallons of Sunoco 104(IIRC) to the tank and ran twice. But had problems spinning at half track, yes half track I was spinning 38"s! Even told a official that there most be oil on the track. They looked and there wasn't any. 3 run I heated the tires up extra, staged and was pulling strong all the way through the traps. When I backed off the exhaust note was different, looked behind me and there was a cloud.
So I parked it and went and sat with my GF and his wife while he ran a few more times. I sat next the the GF and said "if I hurt the motor there goes your engagement ring"
Drove it 40miles home and found #2 had a hole. Less than 2 months later was running again with the L motor. :-D
What was the cause? Tune? Injector? I really don't know!
Sal @ PSP personally dyno tuned it. I drove 1300miles round trip to have him tune it. After the dyno he test drove it and it detonated some. He adjusted tune and was fine after. He was one of the best L tuners in the country. Even started NLOC! Was he used to tuning big *** trucks? No, so it's possible that the loads were different and timing to high. Also I believe at the time of tuning it had straight gas. Shortly after being tuned is when a lot of places started going to E10. Which has a different stoich factor and runs a little leaner.
Later found out that the Sunoco race fuel also had Ethanol In it which change my stoich even more. So that could be it.
I monitored MAF counts and although they did get closed to being maxed out it never.
Guess I will never know 100% what happen.
Let me find some pics.