I use to have a 4150 from BLP that feed my 548 no problem at all. I bought a 4500 and it made no, 0, not a thing, difference. Matter of fact my motor builder was so impressed by it he bought it. I should have kept it. It flowed a good bit more than BLP even advertised it.
This is a good story on custom carbs, a buddy (local engine builder and owned his own repair shop) always said I was crazy for buying custom carbs and I told him he was nuts for not. He felt his were as good as any custom would be. One winter I made a deal with him on building my motor I'd send his carb (1150 hp holley) in and get it redone. Following year he bolts it on (never had drivetrain out over winter) picks up .15 with just setting the idle, a jet change and it was .18 faster. I was not shocked but he was. A lot of good carb builders out there, very few great ones, they know their stuff and it shows on the track more often then not.