Well, the last thing I need is more problems.
I feel pretty optimistic about the plenum though. I mean, you can see how haggard everything else was...yet the butterflies were still intact.

Does the shaft extend through the manifold at the back? Also, what is the ID of the manifold hole? It looks larger than the 1/2" OD of the 19/64 ID McMaster Carr drill bushing shown. I looked up the bushing in the catalog, but was thinking I could just get a 1/4" ID one from Ace Hardware and drill it to the proper ID. I just had it off last weekend but did not realize the throttle leak was my problem until after it was back together. I noticed it was loose, but seemed to be working properly. My idea is to just wire the valves open and epoxy the shaft ends to seal them temporarily till I have time or money to repair it properly or swap in a 4M40. I can get to the front fine, but the back will be a little tight and probably require removing the plenum and in that case might as well fix it properly. What are the implications of driving with the high idle 1500-1900rpm in P/N and 1000-1200 in D/R? It seems to drive fine otherwise, seems like less low end power with them wired closed, better overall power with them wired open. Thanks!

No, the shaft doesn't extend all the way through the back...there is actually a freeze plug there.

I believe the hole is about 15mm. It wasn't really possible to get the calipers in to measure the hole, so I did a ballpark measurement of the freeze plug in the rear. The bushing is smaller than the diameter of the hole, but the viscosity of the epoxy made it easy to center. I also used 24 hour epoxy so, as it cured and thickened, occasional rotation of the shaft would help center it.

I personally didn't want to try to drill bushings to the correct diameter, just so I'd know that I'd have a nice, accurately machined bushing surface.

OK, a little carb cleaner spray to the back answered that question and a trip to Ace only found steel bushings...1/4ID x 1/2OD x 3/4"L $2.79ea we will try Lowe's tomorrow for bronze.