Re: Engine Question
Paint work is 90% prep and 10% materials. I used rust-O-lieum, sprayed on with my paint gun, primer then flat black for the frame. Same stuff only gloss black for the bolt ons. I think it is more important to spend a lot of time removing the old grease and grime than to
<figure out a good coating that will stop rust and yet thick and durable>
Most any old paint will stop rust IF APPLIED RIGHT, and I don't think there is any paint out there that will stand up to rock chips or scraping across rocks. When that happens now it's just a quick touch up with a shaker can.
Good luck with your project.
For rusty areas, I use a needle gun to remove loose flakey rust, then treat it with "Extend",
If your not living on the edge, you're taking up too much space.