8 3/4 Swap Necessities

[MOPARJ]

I am progressing towards putting a 8.75 in my 73 Duster in place of the smaller, but still strong and noiseless 7.25. I have a 489 casing. Can I use the same u-joints, or do I need different ones? I know about shortening the shaft, but how much? 2.25"? Also, im missing some wheel studs. Where can I get those? Anything else I need?

I currently have a 3.55 Sure Grip chunk. I am worried that this will be too many revs on the freeway at 65 MPH. (3400? 235/70/15 rear tires currently). I drive this thing often to cruises 20-30 miles away on the highway. The motor is not the freshest in the world either, with 90,000 plus miles on it. Is this too much gear, or should I have less to keep from wearing the motor out faster?

 

[TheDemonator]

I have a 489 cased 3.23 suregrip... I am thinking of going to a 3.55, 3.73 or 3.91.

I am going to be running an 833OD 4-speed, so maybe it won't be too bad on the open road. My thinking is that I will have what works out to be a quick "3-speed" on the street... but running in O/D on the highway will make a 3.91 rear run like a 3.00, or there abouts.