I'm a New member with a little bearing trouble question. I have a 87 and want to put in new bearings in the engine. The rod bearings have a marking of .0005 OS on them and the Mains have a marking of .0006. What size of replacement bearings should I buy.

Tanks

Probably your choices of bearing sizes will be limited to standard, 0.001" undersize, the 0.010 undersize.
I probably would Plasticgauge the bearings, then choose between standard and 0.001" undersize to keep the bearing clearance around 0.001 to 0.002"
Why do you want to replace the bearings?
Usually if the bearings are a problem, there are other problems.