Performance flat out sucked before regearing with the 38's. I drove the truck around for 2 weeks on stock gearing, and you could feel the strain on the truck, even driving around normally and babying it. I strongly suggest you re-gear immediately after getting the tires, or don't wait any longer than I did, a few weeks tops.

Greetings Cashel! Hope this finds you well...I am wanting to add 38's to my Ford after adding a body lift, how bad was the drag and performance before you were able to regear? I originally planned for 35's, but after seeing yours and a few others on 38's, I don't think I would be happy with the smaller tire. Any advice?