Have the dealer run you a “Detailed Vehicle Specification – (17 digit truck serial number just above the bar code on the window sticker) It’s about 10 pages of what the truck has, and what is doesn’t have, which are called,’less’. For instance, the running boards-platform are stock designation: BLBAQ. THE 18X8 CAST ALUMINUM-TYPE 1 wheels are D2UBE. It’s Fordspeak for that very truck’s inventory of parts.
AFAIK, this exact truck, the 7.3 Godzilla gas V-8 only comes with either 3.55’s or 4.30’s. I’m really loving the 10 speed and have already glommed on to the manual shifting part on really steep hills, up and downhill as there is more engine braking from this gasser than my old Cummins 5.9L with 6 speed.
The Ford 6.2L gas V-8 and 6.7L diesel get the 3.73.
We just got back from a camping trip to Death Valley with lots of 4WD, low range, a little E-locking rr diff. The over all mpg from about 1K miles on the clock to 1500 miles was 12.3 mpg. Not bad considering during that time we had 16K feet of altitude gain and loss and a few sections @ 9% grade for 20 miles. One stretch from Bishop to Lone Pine ( mostly flat) got us an unbelievable 14.0 mpg. That’s with the camper on and loaded up.
2020 Ford F-350 XLT FX4 4WD SRW SB SC 7.3L Godzilla Gas TorqShift 10R140 397 amps dual Alt dual batts Frnt Dana 60; Rr Dana M275 E-locker 4.30's 4580/4320/4066# payload 7243# curb wt. 11,300# GVWR 5-er prepped. 2020 Northstar Laredo SC, 12v compressor fridge, cassette, 320w Solar sub zero insulation.