I have a quickfuel 1050AN that has been messaged by them to gain more CFM. Flows over 1100. I just had them go through it and update with newer style billet metering blocks. It will bolt onto a 4150 or 4500 manifold. Very nice peice. Made 1060 HP on my 632. I can send pics if you like. I also have a BLP 4 hole transition spacer that helps it on a big motor.