3rd gen Engine replacement

I just want to get a general idea of what’s out there. I’m thinking of replacing my engine, 3.4L, in my 2002 4runner. It currently has a JDM, but the milage is unknown. Nothing wrong with it, im just thinking for the future. The options i have are; rebuilt (keep same engine), JDM (milage can be off), or remanufactured (similar to rebuilt). Any thoughts or builders?

 

If you do a compression and leak down test and everything is healthy. There is literally NO reason to even think to replace the engine.

 

This.

JDM swapped engines normally have less miles than US variants they replaced (you can look up why) and even then, plenty of US models have well over 500k documented miles

I got rid of two different 5VZ equipped vehicles with 300k miles on original engines

 

In this economy don’t do it unless you need it.

However, if you are looking try getting a 1kz diesel engine. You’ll gain range and diesels are cool. It’ll be more involved.

 

why replace it ? unless previous owner did hardly anything...those engines, if kept up, will run almost forever