How convert to a Mikuni carb

[RustyR58]

My old Bing is in pretty bad shape, so am trying to convert to a Mikuni (can't remember if I bought a 28 or 30 mm). The whole set up is about 3/4-1 longer than the Bing and I can't squeeze it in-intake rubber is too long and it hits the pipe. How are others making this conversion? Pics?

Thanks in advance!

Rusty