I am running 2400-2500 at 65-70mph which is where I was cruising at. I wonder if it is a strange stack up lean condition at that specific RPM. I do have 2.94 gears right now. Just to experiment (in a safe controlled environment of course) ran up to 4000rpm in top gear just after the surge I noticed. Engine temp dropped down from 200 to 190. Not sure what speed I was traveling, not passed the 55mph I am sure, but it definitely was dumping more fuel. So, that said, how do I richen up the 2400 ish rpm? or is a gear change needed to bring the carbs into a happier place?