I am trying to do the same with a 72xl lens on a Linhof Technikardan and 6x17cm chinese roll film back. Found that the back is 43 mm deep so its a struggle to get the lens close enough to the film. Linhof&studio in the UK will try to put it into a 20mm recessed Technika lensboard and its not going to be easy because the front element is so wide. They are going to see if they can build all the controls out of the recessed part because it will be impossible to operate the lens as it is.
Adding a picture of the problem.