My old crank had a few scratches in the journals, it needs to be polished, the bearings were marked .020 and .010.
I got a hold of another crank that has the same casting number. It's never been out of the engine before so I can only GUESS the bearings are standard, unless it was a factory undersize or who knows, maybe somebody HAS been in there... anyway, I can't find anything on the bearings saying what size they were. The journals all look amazingly smooth. So I'm hoping to use that crank without having to have anything done to it. I talked to a machine shop about measuring it for me , and they want 65 plus tax to mic the crank, and said they are so busy there will be at least a 2 week turn around on it.
Should I buy a micrometer and measure the journal diameters? then what? sorry for being so lost here.
its my first bottom end job.

 

Sure. Then you'll know what bearings to buy.

If the journals are all smooth and don't vary in diameter from spot to spot, you should be able to use the crank without further work.

 

is that all I need? I read somewhere that I need to measure the bearing caps with a bore gauge.