It's just the name I had one working good on a cammed, headered 318 stock 360 heads and 7.5 to 1 compression truck no bog and dam would it pull especially compared to a 600 eddy and a 600 holly. now I ran my best times with the truck with the 750 vac of my 440 but never had the thermo yet so only seat of the pants comparison. (and the thermo relly pulled past 4000 maybe better than the 750 Vac??) course when I sold the truck it went with the 600 holley and the thermo bog went on my 1980 360 truck just replaced the needed to be rebuilt thermo bog that was on it and many happy motoring years with it.