Thinking about a long roadtrip

I'm considering the idea of taking my 70 Duster on a 2000 mile roadtrip this summer.
As it stands right now, the car is:
1970 Duster, mild 360, edelbrock 600 on a '70 340 cast intake, 340 exhaust manifolds, 904 trans with stock convertor, and 8-3/4" with 3.55 SG. It's got a complete TTI exhaust system with Dynomax mufflers. Also big bolt pattern brakes and 15" ralleys.
I have some work to do first, as none of the guages are working, I want to install subframe connectors, and swap gears for the trip. I have a pot with 2.73s sitting out in the shop.
Oh yeah, I'm going to be trying to keep up with my buddies, they'll be in a 2000 z28 and a 2008 Mustang GT. So between fuel economy and OD gearing I'll have my work cut out for me.
Any roadtrip ideas, suggestions, recomendations?