After many ski seasons & 300,000 miles driving up very large mountains, I end up spinning a bearing on the #3 cylinder. It's the 4A-LC engine. I dropped the pan replaced bearings and drove it daily another TWO Years!? Still runs but crank is scored, like no other. This was my first car back in high school 1990's and want to know if I can replace using a crank from any 4A engine from 1984 on up??
It's very iffy and debatable. Not recommended. When dealing with an engine it is better to change all the parts. I'm not saying to do a complete engine rebuild, but rather a minor rebuild. If a head light goes out, change both of them because the other one will eventually burn out due to its time. Brake pads should be changed in pairs as well as shocks/struts. I hope you get the picture... It is imperative to do it this way for engines because of all the movements of the mechanisms inside that wear due to motion. One part change can cause the rest to fail because of wear and the "unevenness" of a natural cycle or motion.
Do you know if all Toyota 4A cranks are the same 1984 up through the 90's?