These flutes, trumpets, air horms, ram tubes, velosity stacks you talk of, are the same or similar for many sidedraft carbs. One brand you can get are Redline. This is what I have. Redline 40mm OD ram tubes. They come in 2 lengths, I have short due to little clearance on the 2T-G. Filters are Redline also. You can buy long or short, for 40mm or 45mm carbs.