I had the same problem with my 87. No amount of jetting would fix it. If I held throttle wfo on the highway, it would almost hit a wall. Almost like an ignition cutout for half a sec, then it’d go back to attempting to accelerate, until it did it again. If I backed off a little I could nurse it a little faster, but it never really worked like it should. This is with the older non CV carb. I know the dub doesn’t have an ignition cutoff and I also know what valve float feels like and it wasn’t that either. Seemed to only happen in top gear with the load of having to cut through the wind. In lower gears not a problem. It’s good to know if I get another tee dub there is a fix for it. :) Charles.