Wheel Size change not working

[bnjmnalan]

2006 GMC Sierra 5.3L, extended cab, 35" tires
InTune I3

What I do: install standard tune, 87 octane tune, change parameters, wheel size, 34 in.
Result: speedometer immediately jumps to 120 miles per hour when driving at idle.

What I do: restore stock tune
Result: things seem to go back to normal, speedometer is still off by 4 miles per hour dur to oversized tires

What I do: install standard tune, 87 octane, do NOT change parameters.
Result: seems to drive normal no noticeable change during short test drive. Speedometer still off by 4 miles per hour due to oversized tires.

What I do: change parameters, wheel size, 35 in.
Result: speedometer immediately jumps to 120 miles per hour at idle speeds.

What I do: install standard tune, 87 octane.
Result: speedometer still jumps to 120 miles per hour at idle speeds.

What I do: restore original backup.
Result: back to normal, speedometer still off by 4 miles per hour due to oversized tires.

It seems that every time I try to change the wheel size parameter it only saves it as zero or near zero inches. How do I get it to save my wheel size changes?

At the moment, what I want to do is install the standard 87 Octane Tune with a 33.75" tire size. If I can get that installed I would be good for a while.

Where do I find more detailed information on the other user adjustable parameters?

[bnjmnalan]

I currently have the 87 Octane tune installed with no other parameter changes. I have attached the files from my tunes folder if anyone can help with this.

Thank you!