I've got a 40 Merc on my tank! 17.5'x 48", all 3/16th aluminum and it pushes plenty for me. The only thing that has been changed is the prop.
By GPS, it ran 32mph with two men, shotguns, a dog and 3 dozen decoys on Wax lake. Since I can't aim for crap, I'm sure there were also several hundred rounds in the boat as well!
While I don't know the speed, it would still get up on top (took a while) with 28 sacks of crawfish, two men and 150lbs of bait!
I don't see me worrying about spending $600 or so on new carbs to gain a few MPH. BTW, I don't know that they cost that much but, I'm sure they aren't cheap!