Hi guys, I have the original alpina b2 airbox and Solex carburettors.
One thing I don’t see in this thread are the rubber gaskets that mount between the airbox and intake runners which from memory are a couple mm thick.
I will try to snap some pics tonight, but I guess they would give the clearance you need. I am sure that can be easily replicated.
Please do! Easy enough to make. I’ll be sure to complicate the process however by adding technology to the equation.