thought I would post my results after putting in Mikes 93 tuns in my 08. I would have to say that I am pretty happy. I pull a 42' goose neck car hauler with a lounge in the front the whole rig weights in at or about 21500-22000.
I have 410 stock gears running whatever the stock tire size is on the factory 20" rims.

I noticed three things
1. from a stop it sure seems to get going with out as much pedal when just taking off nice and easy.
2. I stay in overdrive a lot more and it kick down slower than before.
3. according to the idiot meter in the dash I gained 1.5 miles per gallon and now get around 8 mpg. I am not to worried about MPG and do not drive with them in mind so I am into the gas pedal and getting where I am going.

I pretty much tow the same route from my house to the racetrack so I really could tell a difference. I found out after I put the tune in that 93 is not at all the stations around here but most have 92 and most BP have 93.

After reading the gear swap posts I have know decided that I want 4;56's which I think would make this truck about unstopable. At 70 in OD I turn 2100 rpm if I could get that to 2400 I doubt I would hardly ever even drop out of OD.

Next up I need to figure out why my trailer brakes work great when I hand operate them using the lever on the factory brake controller but not so hot when just using the brake pedal. ANy ideas?

 

Just an FYI BP 93 is a 10% blend since 2009. So I would listen for detonation on real hot days. Hopefully it will be fine.

 

octane is octane, ethonal or not. if its 93 octane you won't have any issues even with an ethonal blend. I had a discussion with Mike about this very subject since all of our 89 octane up here is a 10% blend.

Boss, I know you know what I think of the gears. If you can stomache the cost, it really does make a significant improvment. I'm also fairly certain it would help your towing mileage however I'm also fairly certain it'll hurt your emty mileage. Keep in mind that you also have the newer 3 valve V10 and 5 speed torqueshift which is nice improvment over my old 2 valver and 4R100 4 speed trany.

 

sle not worried one bit about the fuel. I put the old girl through the paces this past weekend towing and did not hear any complaints from from the truck. My big issue with doing the gears is that on one hand I own this truck free and clear, on the other hand after doing a nation wide search the cost difference between my truck and an 08-09 f450 6.4 is about 6500 bucks. The pluses are i OWN this one. The negatives are are............well I would be out 6500 bucks plus some dpf removel costs and some new tunes. And I love the those 08-10 f450's. I put less then 7000 miles a year on my SD since my construction company went bye bye along with the rest of the economy. Logic would say keep what ya got, emotions are sometimes stronger!

I did not hear even a hint detonation and it was plenty warm out.

And with that all said pretty sure I am going to just run what i got as doing anything else would illogical.