I did a rebuild on my transmission and I'm breaking in my rig after buying it in October. I've got a ways to go but I did get her up to 62 yesterday. That was a good step for me. I'll break 65 soon and edge closer to you guys.
I was going 70 with no problems. I was also keeping up with traffic which is kind of weird for me since people are usually riding my tail or blasting past me on the California freeways. Realized later my speedometer's off by ~10%. Things suddenly became more clear. Ran fairly smooth for 77mph on overused Cal freeways.
Here's a couple of vids from mine. This is off my cell phone. The truck is very quiet and has minimal vibrations at that speed, but the microphone on my phone must be very sensitive. Anyway, I've pushed it up to 80 and beyond several times and almost every day I drive it I hit 75 or so just with traffic. When I first got it, I had it over 90. I'll try to get some vids of that, if she'll still pull it.
I regularly Free Wheel down from Mt Bachelor at 75 plus..all you can hear or feel are the Mud T's roaring a little, there are of course NO tight turns in this section of road @ 75 no way it would hold any g-forces in a tight turn....
Going UP to Mt Bachelor I regularly get down to 40ish in third (4spd) and all you can hear is the 2F roaring at 3K rpm..I get passed a lot..