I new that the airbox would prove tricky to install and it was the case. As I'm installing an engine combination (parrallel valve 180hp with vertical induction injection) that Vans does not sell, the airbow has to be adapted.
The installation begins sith the bolting of a flat part to the injection block, then another part (with the flanges) is bolted to the first part. The second part has to be aligned horizontally end vertically with the scoop on the cowl.
The picture shows the two parts and the injection block.



And this is the scoop showing the correctly aligned part.



Then small clips that will hold the airfilter are installed on the lower part. One of the clips is not riveted its position will interfere with the mixture arm on the injection block.



The picture shows the airbox installed, the mixture lever has been removed and it'svtravel drawn on the box.



The kit includes a small part for my type of installation (quit cool on Vans side as they don't support my configuration).
The small part is to be riveted to the lower part to allow for full travel of the mixture lever.



But I still have a problem the cutout is not deep enough.
The solution is to fabricate a new upper plate with holes moved 3/4" to move the plate to the opposite side of the lever.



The cutting proved easy but I somehow managed to wrongly drill the holes for the lower plate and the alignment is not very good. I'll redo the plate as soon as I can get new raw material.