The old steel pan has a very small drip. Not surprising considering how beat up it is. Nowhere near as bad as the ACE pan. I have a new problem now however...
When the car is driven for a few minutes, oil pressure gradually goes down and down, and pressure degreases with RPM. It got down to 10PSI by the time I got back home. After the engine was cooled off, pressure went back up to 40 at idle. The hamburger pickup tube has holes for 2 bolts instead of one, but I couldn't get the second one started because it hit the front cover. I figured maybe I used the wrong o-ring, and needed to add that second bolt. So I took the pan off again, used a different o-ring, and managed to get a shorter bolt in the second hole. Put it all back together the same way and waited until the next day so the RTV could cure. Still has the exact same problem.
I still think the pickup tube is sucking in bubbles. This would explain why pressure would gradually decrease as the oil gets aerated, and why pressure would go down with RPM. This tube has a very short length after the mounting flange that goes into the pump, and the o-ring sits quite a bit closer to the flange than the other pickup tube. My guess is that it's just not getting the o-ring past the bevel in the pump. Or maybe there's a pinhole or a crack in the tube that I can't see.
To answer your questions, yes, I have the ACE pickup tube. It's too short to fit in the hamburger pan unfortunately. I did clearance the windage tray for the tube. I haven't measured the tube, but there aren't any witness marks on it that would indicate that the pan is touching it. My transmission bell housing doesn't have the lower bolts that go to the pan, so that also isn't coming into the equation.
I've considered taking the ACE pan to a machine shop to see if they can fix it. I'm getting a little hesitant to spend any more money on it though. I haven't talked to ACE yet, but I don't think I'd trust him to do anything other than send me a refund, and I doubt he'll do that. The welds do look better on this one than the first one he sent me. I would wonder if he sent me back the same one otherwise, since it leaks in the same place.
I think the best long term solution is probably to get a tubular k-member with a rack and pinion from Overkill Racecars. That's supposed to give you at least another inch to play with. That would allow me to fit an unmodified pan in there. That's expensive though, and I won't be able to do it right away. There's a possibility the headers won't fit too, which would be another expensive problem to solve.
The smartest thing to do might be to park it until I can afford better parts.
Guess I'll call a couple machine shops and see what they say.