Edelbrock performer #1406 is superb for the 350-400 HO, runs very nice out of the box. I've had one for two years now, replacing it with Quentons original 1968 carb he sent me. The problem I had with the 1406 was simple: GAS MILEAGE! **** thing sucks alot of gas, too much for my driver '68. And it demands 93 octane for an FGF configuration, nothing less.
Of course, my lead foot could be guilty to some degree for the bad gas mileage.....I suppose.