well...that didn't make me happy
i'm doing the same thing...running 91 octane on my 87 perf tune...just cause wifee f'ed up and put that in, i raised the timing 2 adjustments and everything seems good, but.........i better put 87 back in or run the canned 93 tune i guess.
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2008 f150 supercrew, 5.4, 3.73 LSD, tonneau cover, 275-65-18 BFG's. Gryphon programmer. XLT with XTR package. Tinted heads and tails with 8000 HID's. 4300 in the fogs. Gott's Mod. Painted grill.