these carbs are setup to be used with a fuel pump, if you look at the inlets they are pointed down instead of coming straight out of the carbs, also the pumper carbs have a smaller needle and seats in them and dont work well when gravity fed. fuel pumps are nice because you dont have to run billet bowls or cut one float off like ya do with the gravity fed carbs.
eric is a stand up guy and has some real nice stuff! i will vouch for him!
if ya need anymore info on setting up a fuel pump or which one to buy etc.... feel free to pm me