[Gaz64]

Paul,

I ran a large rectangular K&N airfilter which surrounded my 4 IDFs.

I made 4 plates for the carbs and one large plate that screwed to the individual plates. The airfilter then sat on the large plate within a folded lip.
I made a matching top plate which had a step to keep the filter located correctly and not suck in.

If I wanted to tune the carbs, I just took off the top lid.

If I needed to take one carb off for some reason, only the large plate needed to be unscrewed from the carb plates.
This way I didn't have to undo 16 ramtube nuts to get the large plate off.

The carbs shared the same filtered air, a plenum of filtered air they could all draw from.

I copied this idea from Ferrari, although theirs is an enclosed airbox.

I would have liked to do it this way, but I couldn't find a way to run ducted air to the box.
If I did again, I make the base plate larger in all directions and run a vertical sheet metal wall to seal against the bonnet with high density foam.
My bonnet had a functional reverse facing scoop.