Chevy P-30 w/454 owners?

You have gotten a lot of good advice so far. Most off us with a 454 P-30 chassis are heavier than yours and are working a lot harder. Not mention yet is the IFS front end. Check the ride height on the front end. I spent a small fortune on it. The newer straight front axels are much simpler. Check also the ball joints and other front end components, also I had a ball joint let go on a trip last year. Older cooling systems are always suspect. Your radiator can be checked with an IR gun from the inlet(where the thermostat housing is) to the outlet(lower radiator hose) in a 2-4 in grid pattern. Look for cold spots in the center of the radiator indicating blocked tubes. Also you should see a 50 degree change in temperature from top to bottom if your radiator is cooling effectively. Headers will eliminate exhaust manifold leaks and add about 80 more HP with a cooler running engine. I have 107k miles on mine and the engine and transmission itself has not been a problem(yet). It seems like every trip something fails and needs to be replaced or fixed so expect some unknown problems and enjoy your trip.