Gearing and SCT question

[DMash1080]

Trying to gain some knowledge. Did a search couldn't find anything. If I added 37" tires....of course with a 6" lift...would I need to re gear. Would be an 06 F250 SD...so obviously 3.73 gears. Also....will the Livewire recalibrate the speedo for me or no? I want my actual dash speedometer to be correct, I don't want to refer to a module for my correct speed.

Thanks

[Granny]

As far as re-gearing you do not have to but you would need to. The Livewire will not re-calibrate your indash speedo. I am sure there will be others along shortly who will also chime in with their opinions. I hope this helps.

[DMash1080]

What would be the best gears to re gear to? and how do I go about recalibrating my in dash speedo then?

[Granny]

I am being told probably 4.30s. As far as your speedo, the dealership may be able to re-calibrate it to a certain point. You can also get a Truspeed. It is a electronic device to recalibrate your speedo.

[Big Mule]

I just put 4.30 gears in my beast, 100% difference towing my fifthwheel in the mountains. I have 33'' mickey thompson atz's and I am running 2200 RPM's at 65mph, so I would think 4.30's would be perfect with 37'' tires. My truck pulls harder and faster up steep grades without my tow tune due to the gears. ( should have been my first mod) The dealership can do your speedo for 100 bucks. I also gained some fuel mileage pulling my fifthwheel.

[DMash1080]

Well I will be doing pretty much NO towing...like maybe twice a year tops. So I was thinking maybe 4.10's instead for highway mileage and all.

[DMash1080]

Any other opinions on 4.30 or 4.10??