I did mine, I had more than a little noise. Used a piece of metal tubing held to my ear to nail down the noise, till I was fairly certain it was in the bottom. Checked the side of the block near the distributor to see if I had any oversize bearing letter codes. Before I started, I took all the plugs out, put it in neutral and checked (with a torque wrench) how much peak torque it took to turn the motor over one revolution. When I was finished with the new bearings, checked the torque again, I know I'm anal (I#ve seen guys put in new bearings and not be able to turn the motor over with a cheater bar, they don't last long). Ordered a set of stock bearings, a set of 0.001 over and a set of 0.010 over. I didn't need the 0.01 or the 0.010 and returned them. I cleaned up the orignal bearings and the journals and checked them with plasti gage, they have to be clean plasti gage melts in oil. The top half of the bearing had significantly more wear then the bottom half on mine. Put the new (stock size) bearings in and plasti gaged them again (I know I'm anal). I was lucky there was no major scoring and the bearing surfaces were a fairly constant diameter end to end, there was no significant cone shape to the crank journals. I cleaned out the oil pump and checked the tolerances while I was in there, the bottom of the motor was fairly clean. I had to make an oil pump gasket, the oil pump got pretty tight without the gasket.
The book said you can mix different sized bearings to get the right tolerance. I was happy none of mine were near the outer tolerance, after new stock bearings.
My motor was a lot quieter after the new bearings, so I'm guessing that was the problem. I drove the motor easy for the first 500 miles and kept the RPM's down. Used fossil oil instead of synthetic.
The rest of it is just like changing the rear main bearings, I did that also while I was in there. I checked the timing chain play, the flex plate bolts and looked for flex plate cracks from the motor side of the flex plate. While I had the connecting rods off I jiggled the connecting rod up and down, just to check for wrist pin play and looked at the shape of the cylinder walls.
Just an opinion, but slightly loose bearings last longer than too tight bearings. Thinking they are going to wear in before they burn up is often wishful thinking.
