The factory oil clearance allowable limits will be more than what I consider to be a good fit. I'm sure this will get alot of feedback, because some guys think loose is the way to go, but .0018-.002" is what I like to run on the rods, and .002" to 0025" on the mains, but I prefer my engines to be closer to .002" on the mains also. Sometimes, depending upon the housing bore dimension on the rod and main, it's hard to keep bearing clearance tight even if your crank is on the "high" limit. The factory usually allows an extra .0005" on the rear main.
If you have a main or two that ends up with almost .003" clearance, don't panick, you'll be okay.