An update and some additional information: At about the same time I started having carb problems my water temp gauge stopped working. Something that mystified me when I changed to the weber was that the gauge started working again. About the same time I started having the above problems it quit working again. About half way home tonight I stopped to get gas and check mileage--30.22 MPG. I don't know exactly how all this figures in with this only happening at speed, but I was thinking this is an electrical problem-vs-carb problem. For whatever reason, when I went to pull out at the gas station my temp gauge was working again. It worked almost all the way home and I cruised at 65-70MPH with no studders or problems at all. As I said, the gauge wasn't working when I got home so I decided to take my first ever look at the fuse box in hopes of finding a loose fuse or something. In all my years of messing around with old cars, I have seen some crazy wiring, but I can honestly say I have never seen anything like this:
The third(wire) and forth fuses from the top on the left side are labeled IG/meter turn and regulator. The fuse was slightly corroded and the wire loose. Pulled fuse/cleaned and tightened the wire and the temp gauge started working again. Guess at the very least I am in the market for a fuse box and if this is indeed the problem I might not of needed a new carb, but can't say I regret getting the weber.... Anyone have an extra fuse box for a '83?