Good article on Dot 3 and Dot 4 fluids.
https://www.autozone.com/diy/brakes/dot-3-vs-dot-4-brake-fluid
I also like to use Dot 5 on restorations, not only because of protecting the paint, but Dot 5 does not draw moisture like other brake fluids. Seen it many times, car is restored and then stored for several years, owners sells or wants to drive it and brakes are junk leaking fluid. Read the article Dot 4 draws moisture even more than Dot 3.