Have you checked with Hughes Engines? They still list them on their page, not sure about actual availability.
Hughes Engines
I looked for pictures, apparently I don't have them anymore. Here's a picture I found in autoxcuda's install thread showing the pickup
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On mine I had to move the mounting tab to work with the original 340 windage tray. Of course, I had to do the exact same thing on the pickup that came with my Kevko pan, same deal. And the Kevko one I had to bend to get to the right spec on the bottom of the Kevko pan, it was a good 1/2" off the bottom as I received it.
I guess I shouldn't have singled out drag racing. Putting your oil pan below your K member is stupid. I mean seriously, you think that making your oil pan one of the lowest parts of your car is smart? Even on a car that isn't lowered that's not real bright. On something lowered and set up for handling like the OP's car it's flat out dumb.
Of course it matters that it wasn't a road race pan. You have absolutely ZERO knowledge of the oil pan being used. None. You had one Milodon pan, it was a completely different pan than the one in question, and you got rid of it. How long ago was that? I have a road race pan. The welds are great, it doesn't leak. It's one of the nicest oil pans I've seen, and I'll buy another for my Challenger when it goes back on the road.
The added ground clearance is nice, as the milodon road race pan actually sits a little higher than a stock pan. The additional capacity is a bonus as well. But the real improvement is oil control, the road race pan has baffles and trap doors to keep the oil near the pickup during cornering loads. Most of the other pans out there are built just to control front to back oil movement, not side to side. The OP has built the crap out of his car to handle, the pan makes perfect sense with his build.
For the Kevko pans, I seriously doubt their circle track pan will fit an A-body. That's just looking at them, you'd have to ask. They also have oil control set up for only one direction. Which makes sense for circle track and not at all for street, autoX or road race use. I have a Kevko pan too, just an M301 for some extra capacity on the 318 for my Dart. The welds on the Kevko look rough as hell, and the baffles and trap doors had sharp edges and slag that I had to clean up when I got it. I'm sure it will work, but it looks like a home built job. It also only has front to rear oil control, which is pretty useless for cornering. Honestly I'd fire up my TIG welder and build my own before I bought another Kevko pan. After cleaning up the work on the pan I got and modifying the pick up I probably could have built my own.