6 michelin xde x265/70/19.5's,
I can't find that exact tire on the Michelin website, so I suspect they don't make it now. But I found the XZE-2, which comes in that size.
Michelin Americas Truck Tires XZE®2
I will be re installing the edge programmer and a gps to monitor speed. I think the 19.5's will throw off the speedo. I will report on how much.
LT265/70R19.5 are very close to 35" tires.
The speedo will be off the percentage of change in tire revs/mile. Your stock LT245/75R17E tires have 664 revs/mile. Per the specs at that link above, the XZE-2 LT265/70R19.5G have 607. 664 minus 607 = 57, divided by 664 = 8.58%. So if your speedo is accurate now, it should be slow by 8.58% with the new tires. 70 MPH per your speedo will be 76 MPH per Officer Bob's radar gun (and a good GPS).
However, any decent Ford tech can correct (calibrate) the speedo. Most dealers will charge you about one hour labor rate for an experienced tech to do the 5-minute job of calibrating the speedo.
Or you can spend about $200 (street price) and DIY with your own calibrator.
SuperLift TruSpeed™ Speed Sensor Recalibrator
One disadvantage of those taller tires is your final drive ratio will feel like longer legs. Your 4.10 axle ratio will reduce by that same 8.58%, so when hauling or towing heavy your truck will feel like it has a 3.66 rear axle ratio. You can get most of that power and torque back by changing the ring gear and pinion to a 4.30 ratio. Then your truck will feel like it has a 3.93 ratio. Or you can change it to 4.56 which will feel like a 4.17.