custom tunes and tire size and gear ratio

[lawrenr2001]

Okay ....when I got my custom tunes loaded and reinstalled my programmer; I checked the gear ratio and it read 3:55 (which is what I have). But when I checked my tire size it was not what I calculated when I first bought the Gryphon (I had to enter it). The question I have ..Did my tire size get calculated by Bill and entered on the custom program by Bill (Bill jump in here if you're not busy)...I gave him my tire info when I sent in my Hex code and list of mods. I thought I had calculated the right tire size...even subtracted 7% for squish....the custom tire size that the program had was something in the 2400s and my figure was 2654 (I think, I have it wrote down on my instruction book in the truck, not here at the moment)....my tires are 35X12.50X20...The truck speedometer is only a mile difference with my figure from the programmer (which is lower 1mph). It is not causing any problems, I just want to make sure I got it right for my MPGs (not that is a big concern, I love the new muscle). Also, I ordered a 93 performance program and I haven't used it as of yet. Everytime I changed gas in the past (before programming) my truck would run bad (backfire, cutout at 65-75)....I spoke to Bill about this a couple of months ago....Ford had to replace some plugs at 4000 miles after the first time I did this and never explained to me why, they only recommend that I run it on 87 octane "cause that's what is was design to run on" (their answer)....If I take a chance on Bill being the wizard I suspect he really is, since he built me a custom 93 program did he allow for the timing for 93 or as I have read, will I need to advance the timing 1.5 (? .5 per octune rating??).....OR should just leave the damn thing on 87 performance and continue to be stoked about the new power?????? .... I am itching to run it on 93 just to feel the damn truck run like it should have to start with (it only has 30000 mile on it).....sorry to have rattled on about all this ....but ...hellll..I' m welding engineer not a damn mechanic!