Performance AFB 4119,4120
You will want to play with the counterweights reducing the weight a little at a time until you notice a bog, then add a little weld back on. Keep track of your weights every time. Also there is an auxiliary feed hole in the very bottom of the secondary boosters it’s as close to a secondary pump shot as you get from a Carter. You can play with orfice size. Thin the throttle shafts, boosters, be sneaky and get creative. Also be sure the primary booster pickups are not choked way down at the very bottom. Open them up.