Yea, but if it runs good, and there isn't excessive thrust play, why?

You still have about 500-750K before it is time.......

 

You do not have to fool around lifting the crank up. You put a piece of dowel in the oil passage that sticks out just enough to catch the bearing shell, and turn the crank to "roll" the old upper shell out and then do the same thing in reverse to roll the new shell in.

But in general, I agree with Pat. If you have good oil pressure, etc. why fix something that isn't broken.

EDIT: Sorry -- I see you are worried about the thrust face falling off, as mine did. Are you sure that you have the old 3 piece style bearing?

 

sorry didn't reply back. My last 6BT managed to break its crank, and I found one of the thrust faces laying in the pan. So, I've decided the replacement engine will have a fresh set of main bearings, and a 1-piece thrust unit. Never fully disassembled the engine to see if there was anything else that caused the crank to fail, but I assume it's because the thrust bearing failed first. Regardless of what really killed the engine, I'm still gonna replace the mains on the new one