I did this a few months ago. Look at it from the point of only swapping out the long block. Use all of the S13 stuff that you can. I used the S14 upper intake manifold on the S13 plenum, and it works great. Don't forget to swap the coolant temp sensors, too. If you use the S13 distributer, you can simply use the stock S13 harness. I'd also pull the S13 cams out before throwing the old motor away. If anything, they're worth a few bucks.

Give your engine bay a bath, while you're in there.