Hang in there, it's probably frustrating but you'll be there soon.
If it we're me, I'd do a compression test right off the bat. You need to find out the health of your engine. With 130K you're not going to have the performance of a newer engine no matter how well you think the truck runs. Take it from me. I would make sure you have the thing running in tip top shape first (good tune up). I would have the injectors cleaned and so forth. Don't just dump a cleaning solution in your tank thinking that's going to help. And don't just go to some shop and have them do a injector cleaning without removing the injectors. I would have what's called a "stage III" done if you have a good ford dealership. Once that's all done, you can put the juice on it if you'd like but your weak link is going to be your pistons and rings. I'm sure you can get away with a 50-75 shot for awhile, maybe even for along while but you're going to risk it with that many miles. If there IS something about to go wrong, you'll probably find it out pretty quick. However, I'm just trying to help you do this the right way, and to help you consider everything so you don't blow something up. If you haven't modded your truck yet then maybe look into doing the intake and exhaust first. (After the tune up and the compression check) Then do some other mods. DO the NOS last.