you can do it, but you will need a switching valve (like on pickups that have dual tanks) to do it right.
the pump in the cell will need a return also. if you dont, this will happen: the pump in the cell will be running at full volume, and the regulator will be sending all unused fuel back to the cars tank, not the cell. in about ten minutes, all fuel in your fuel cell will be empty, and your gas tank will be overfull. not to mention it will be a mix of race gas and 93...which is basically the thing you didnt want to do otherwise you would have already done that...
(cause that is what happens when a switching valve goes out on dual tank pickups....it will drain one tank and fill the other....)