I'm looking forward to the 2011 gathering at Mid America, hope to be retired and want to drive my 76 there and back. I'm fairly uncertain about some of the mechanical condition / history of the car, namely u- joints and and wheel bearings. The overall condition of the suspension, rear end, cooling, brakes, ignition, oil consumption / overall engine performance systems appears to be fine.

Well....I'd say if you're that concerned now, it might be best to go ahead and have them done(or do them yourself!).
I took my '74 on the '99 Caravan to the NCM, then went on up to W.V. for a few days. About 10 miles from my house on the way home, I heard a scraping noise in my driver side rear....the dreaded spindle bearing! . At least it got me home! The car at that time had only 43,000 original miles on it.  That was about a 24-2500 mile trip.(We also took the '85)
I drove the car another couple of years before I actually tore into it and completely refurbished everything on the suspension and chassis.(I don't put many miles on it, so that couple of years was only prolly 200 miles!)
You got time to do it!!
Like ya said, the fronts are not that complicated. The rears....well, they ain't exactly a walk in da park! You might want to just buy a set of t-arms, and swap them out. That's a little more expensive than just doing the bearings themselves, but it gets you a complete assy that you shouldn't have to worry about for the life of the car. Or you could find a competent Corvette repair place in your area to just do the bearings for ya. If you're a competent mek-a-neck yourself, you should be able to do the bearings yourself. Decisions, decisions....

The real problem with a rear bearing taking a dump on the road is parts availability, and the fact that they are such a pita to do, without the proper tools, which no-one ever seems to bring on a road trip!
My suggestion would be to go ahead and plan on having them done before the trip, then you won't have to worry about it.

Dont forget your Belts and Hoses

Joel... how'd ya git soooo smart?

Like Dennis I have the same woe.... I have re-done bout everyting but them arms..... Terry's lil incident outside Looey-ville skeered da ba-gee-bies outta me and drivin longer distances.

Not ta mention I hafta map out every gas station between here and the destination. Maybe someday I'll change dem boogers out. I have time now but am doin a lil sumfin fun in da g-rage right now an don't have room for more auto parts layin round.

I guess that is why I keep a lookin at them enclosed trailers....... sigh.......

I want to drive her, so I guess it's time to find that old piggy bank and start saving for a pair of them nice clean shiny rebuilt arms. Hopefully I can finish in time to heal up before the big ride or I'll just come with the bandages. Time to start planning this thing out - thanks

git `er done...