318 questions...
I agree with fishy68, better look at the cylinder wall and see how much lip you've got at the top of the cylinder. If you've got much more than what you can catch with your finger nail, then you've got a good amount of wear. Also look at the lifter valley and see how much sludge has accumulated, that's a pretty good indication of how well the engine was taken care of. Good running used smallblocks are fairly easy to find if you want to go the cheap route. If your going to do a rebuild, you may as well go the 360 route. Just remember that a truck and car motor have different oil pans and exhaust manifolds. For the record, I have a stock bottomed 318 with ported stock valve heads, 268/480 cam, headers, intake, 600 Holley DP, 904 trans w/2800 stall & 3.90 gears in a '75 Dart Sport. The motor runs fine on 87 octane and seriously gets with the program.