Hey, i kinda missed it again!
They will FIT with out a lift, however you probably wont have much movement. 3 inches will do it. I ran just 3 inches of suspension lift to start. then i added 3 inches of box lift so the rear would work all the way. Next when i did the motor swap i added 3 inches of cab lift. I think it takes 6 inches to get the proportions right. just my opinion. (see avitar) I think you might need some suspension in order for the tires to clear the spring hanges and allow you to turn all the way. Body lift is easy though.
As far as too much gear, I run granny to get going most of the time and skip OD. Where as stock you can start in 2nd (one up from granny) but turn around and run OD. Then when you wana really get her goin' slide her up in to OD and hang on! I did however turn up the multi-fuel as far as i could. The cummins dont really mind,up hill, down hill, head wind tail wind it will run to the governer (2300 for now)
I would agree its like driving a ladder down the road, at 75! only a six wheeler is like a 20 foot extention ladder that wiggles in the middle!
Bring the GPS, the stock speedo bails out at 65!