Newbie help c10 64 what to look for

[crowdaddy]

I'm looking for things to watch for as I'm running my c-10 around trails. I don't have it ready for the road yet, and so far there are three things to do that I know of.
1. replace radiator cap ( guage goes red once in a while, leaks at cap, small)
2. gas cap, just because it is old. Gas guage doesn't work.
3. anyway to tighten manifold bolts to the head? exhaust leak there and noisy

Are there other things I should look out for? I can't really get it out of first gear on the trails. But I'm working with it, cutting wood hauling small, very small pieces of wood. Mostly to have an excuse to run the truck. I'm leaving it running while cutting, figuring it needs to be run. Any harm in running it with the exhaust leak? Thank you in advance.