I've noticed a very small amount of oil leaking on my transmission side of the engine. I also noticed some oil leaking around the distributor that could have been the culprit and replaced the o-ring. If it continues after that and cleaning it up I'm sure it is the rear main seal leaking. It's the only seal that hasn't been replaced. My question is: What is the best way to get to it? Should I pull the engine or drop the transmission, or can I pull the transmission back enough to get to it? The funny thing here is that I just got done doing a ring, bearing, and valve job just a few weeks back and someone recommended it. I didn't do it because I left the block in the car to do the work. Now I may regret not doing it when I had the chance. On a side question is it normal for cylinder compression to slowly improve after adding new rings? Shortly after doing the work my compression was around 140psi on all cylinders and I checked a few days later and it was a bit better. It took nearly 2 weeks to get to 180psi and another week to get to just under 200psi. It took about 2,500 miles to improve to a satisfactory level. Is that normal?

Yes, it is normal for new rings to improve their sealing ability. This is part of a normal 'break-in' period for a new or rebuilt engine. It takes a bit of time for the rings to seat themselves properly.

As for the seal......... if it's a 2-piece seal, you can change it pretty easily by dropping the oil pan and removing the rear main bearing cap, then rolling out the old pieces and putting the new ones in. You should be able to do this without disturbing any other bearing caps.
If it's a 1-piece seal, try separating the tansmission and moving it over a couple of inches to get to it.

I believe the only seals they make for it are one piece design. Thanks for the advice. I'm going to put a piece of cardboard under the car tonight to see if it's still leaking. Everyone keeps telling me to use some form of stop leak but I hate that stuff in every form it comes in. I've never seen any work but once and it lasted for less than a month.

I finally got around to checking it out thoroughly. It's not the rear main seal. The transmission pan is leaking. (color blind)... I'll replace the filter while I'm in there. Thank god... I really didn't look forward to doing the rear seal. It's not a bad leak - 2 or 3 drops overnight but any leak is a bad leak...