Carb linkage and velocity stack questions, Need opinions on CB performance recommendations Options

[Van]

I ordered a dual carb linkage kit and velocity stacks from CB performance for my 44 IDFs... 2 things surprised me - I called them, and was told, "don't worry about it - that's as good as you'll get." I'd like some other opinions...

#1: the air cleaner bases (there's a left and a right) have the same "offset" for the linkage bar - meaning the bar will be at an angle to the engine when it's installed. They said, "We don't have anything for the type 4 offset - don't worry, you'll be fine." I've seen pictures from searches, and it looks like many people have setups with a straight bar - what are they using?

#2: the velocity stacks have a bore which is a bit bigger than the top of the carburetor - like maybe 3/8" larger in diameter. (Actually, the air cleaner base plate has the same large bore, too.) Anyhow, it seems to me, that if one has that large a step transitioning from the velocity stack to the carb throat, any gain from the velocity stack will be eliminated from the turbulence. CB's response, "Don't worry - you'll never feel the difference."

Does anyone have any guidance for me? Should I try to get velocity stacks the right size? Should I modify the air cleaner base plates to make the bar perpendicular to the crankshaft?