Update, finally.
I swapped on my aluminum Offenhauser dual plane intake that I got from somebody on the forum here. Removed the stock one, discovered there's not much more meat on there if I ever wanted to port the heads, they're gasket matched pretty well.
Also, the stock intake has a lot of metal that can be removed for gasket matching. The ports are so open I think if you gasket matched and maybe polished the inside, you could use it for racing.
Here's what the ports look like on the Offy. Dual plane, primaries use the small side and secondaries the big side. Gives more airflow velocity for the same volume for better distribution. Best for improving part throttle, cruise, and idle which is what I need especially for when the AC is working.
So, here it is swapped on there. I had previously sandblasted it and painted it with high temperature clear paint. Hopefully it will stay clean that way. Swapped on easy enough, there was a little bit of work with a file on a couple of the hold down washers and I couldn't use all the washers and lockwashers where it bolts to the exhaust manifold but all in all that part went easy.
The hard part was bolting the damn carb on. First I discovered that the stock studs were metric and the Offy was tapped English. Went and bought English bolts. Then discovered that the threads needed to be chased with a tap. Went and bought a tap set because I didn't have one yet. Then discovered there was a reason there were studs in the first place, namely that bolts won't fit because of the way the carb is. Went and bought studs. Discovered that the studs were too long, had to cut two of them down. Note, Grade 5 studs dulled my hacksaw blade pretty quick. Finished with a file. Finally got the carb bolted on. Here's how it sits now.
I broke the plastic ball and socket on the throttle linkage in the process. I can't find where to get a new one or equivalent; the ones I've found are all too big. I was able to make something that will work out of a piece of hardware that holds window screens in. Don't ask.
All in all though, it runs great. Perhaps after breaking, fixing, and readjusting the throttle linkage I now get all the way to W.O.T.; nevertheless, part throttle feels more responsive, and it idles better too. Using the vacuum gauge for tuning, I ended up putting in 20 degrees of initial timing. Found today that's too much, I've backed off to 15 degrees (spec is 12).
Hope to have the updates coming more frequently, especially since it's getting hot and I really wish I had air conditioning right now.