main cap on. There are 4 numbers stamped on the block for the main bearings. write these numbers down and then look on the 1st counterweight of the crank shaft there are 4 numbers on there. I think the numbers on the crank go from #1 to #4 left to right. Write these numbers below and in order so that the #1 bearing grade on the crank matches the #1 bearing grade on the block, then add the two numbers and that is the grade you need for the main bearings. What part of the crank did you have ground? If you had the rod journals ground then you will need to get undersize bearings. Selecting these requires more knowledge than I can convey in text. Get the help of a machine shop. If the rod journals were not ground then you need to look at the #5 counterweight on the crank shaft. There are 6 numbers stamped there ( a 1 = I a 2= II ) From left to right (#1 rod to #6) write these numbers down. Then look on the side of the end caps of the rods. This is where I say I hope you kept them in order of how you pulled them out cause you need to know which pistons are which number 1-6. Write down the number for each rod #1-#6 and then add the coresponding grade to the number you wrote down off the crank. This is the rod bearing grades you should order.
I don't know what HALO is talking about "have you considered grade 3?" DO NOT RANDOMLY SELECT A GRADE. Each grade represents a different bearing thickness. Grade 1 is not better than Grade 3 here. It is important that you get the right grade.
