I would worry about your drive shaft unless:
A- it already has a vibration
B- you plan on cruising at such speeds for a looong time.
I ran my 95 at 120 + all the time, whenever possible, it had 3:27s. I live in an area with some nice, big, wide, new freeways. Whay happened to the 95? Look at A-trains post, about the tail shaft. I messed it up pretty good, it leaked out the extension housing, right onto the 3rd cat, burned, smoked, very classy.
My 96 has seen 140+ quite a bit, and even 15+ a few times, but I use more restraint, and the tranny doesnt leak. BTW, thats on a stock drive shaft, no vibrations.
"Keep making it thinner until it breaks, then go one size bigger."
My Cougar XR7