The 318 is a great little motor, I built a couple back in the day.
The thing to remember with dodge's or mopar/chrysler is some of the small blocks
came with steel cranks. So if it's a steel crank used a hard bearing. If it's a soft crank
use something like clevite bearings they are a tri metal and softer.
I made the mistake of puting a soft bearing on a steel crank and spun the rods.
I was only doing what my machine shop told me too. When I lived in Florida I
met a nephew of Big Daddy's and asked him to ask Don what I did wrong and he said that was it.
Kurt