Couldnt I take diesel mechanic courses?

Don't need to waste money on school. Just have cash reserve so you aren't pressed for time and buy the tools as you need them. As long as you can tell the difference between aluminum, chrome, mild steel, hardened steel and stainless steel, have a service manual and a good attitude you can do it all yourself. Get you an overhead crane and a counterbore cutter and you can rebuild the engine.
Just need tools and specs. The rest you can learn on these here internets.