I was out on a tuning drive a couple weeks ago and stopped to take some pictures as a storm was rolling in. A few updates:
-I replaced the generic MAP sensor with AC Delco and it seemed to help but hasn't eliminated the problem. It still runs a little rough under light acceleration once warmed up, but only once in a while. Not done tuning yet though. Still have to get into timing, but it runs pretty good - 0-60 in 5.4. It's really slow off the line, but it really pulls once you get into the powerband. I have a 12-bolt with 4.11 gears to swap someday which will help with acceleration. My 3.54 rear end is a little high since I don't get on the interstate with it.
-I have a sway bar and new front coil springs to install one of these days. I regret chopping another 1/2 coil off my springs so I bought new 1" drop to get me back where it was.
-Someday I'll get Vintage Air. Been spending money on wedding stuff.
-The reverberations that I feel/hear are still there at certain RPM's. I might try replacing the rubber engine mounts with nice poly mounts and see if it makes a difference.