Thanks for the tips. When I've recovered from this week's slog to get it back together, I'll start measuring, and looking for the location(s) of oil intrusion.

The problem is, in order to get the bolts started, I couldn't use any of the fiber gaskets. Just the bathtub valley pan of course, which has limited compliance (especially when already crushed once). This intake worked fine on the iron heads and I had no problem with leaks then. Can't take anything else off without removing metal.

In this area it may be difficult to find a machine shop that is capable of doing precise machining on the intake...