a liitle late on feedback ran the 600 all summer seems to run clean .pulled the plugs after about 500 miles to inspect.they all looked clean.loaned the 750 to a friend to use on his lemans 400 cubic inch motor that he drag races.he was running an eldelbrock carb and said the holly ran 3/4 of a second faster.he wants to buy it from me but Im not sure im ready to part with it.I may have dejetted the 750 and used it but gas was 4 plus a gallon and thought the 600 might get a little better milage (what was I thinking hotrods arnt about gas milage)