I bought a 1990 Toyota 4x4 truck about a year ago. The body has 257k, the rebuilt transmission has 40k (have receipt for that), supposedly the 22re 4 cyl. engine has about 140k on it, but I have no recepit proving that, so I'm going to assume it has 257k. It runs decently. Just did a tune up on it and it runs better, but it has leaks out of at least two locations and could use a timing chain replacement before it throws it and fucks everything up.
I wanted a light diesel, but couldn't find one. I've been told you can fit several light diesel engines in the engine compartment, but I have no idea where to even start when it comes to researching that sort of stuff. Which engines will fit, and what are the best choices between those engines? Is it worth it to do it, or should I just take it to a reliable shop (cousin-in-law owns it and would any work I can't handle) and have them fix what needs fixing on the 22re?
Any other advice?