Determining Main Bearing Grades?

[Julian]

Well, I'm trying to figure out what grade main bearings
to get. I have the numbers stamped on the crank:

 1 1 1 1     <-- rod grades
1 0 0 1 1    <-- crank main journal grades

But the numbers stamped on the block don't match what's
in my FSM, it should be one letter followed by five
numbers, what's there is this weirdness:

  V   o
U20 12	     <-- supposed to be block main journal grades

Does that make sense to anyone??????
Please let me know...

Thanks,

-Julian
'92 NX turbo & '92 SE-R