This is what I've done, could be neater but works. The air bleeds are blended, maybe that has an effect on how they work as air bleeds but I cannot tell. These are TM38s
Not sure how long the total inlet tract is but the carb is visible in this photo and gives an idea, good power from 2,500 - 7000 but I doubt the length of that is the main thing. A small change to the exhaust can have a much bigger impact, as can head work. I think the shape of the bellmouth is important to what it can flow and may be more benefit than such a long run as you have in the photos trying for a little gain with optimum length tuning which may be a bit elusive anyway. I'd be seeing what the power difference is with them at their longest practical length compared to the long set up in your photo, shorter may actually work better.