Started working on the air box. This contains the air filter in a fiberglass "box" that routes air from the front of the cowling to the carb. The engine I bought came with one that had seen better days (image one) so I started by removing the old attachment plate. This plate attaches to the bottom of the carb and the air box attaches to it.
There is a drain plug at the back of the carb that protudes into the air box, so you have to cut an opening for it. Using the old plate as a guide I cut that opening. You can see the opening for the carb and for the plug protrusion. The next step is to reduce the length of the air box lid so there is no interference with the cowling opening. I trimmed an initial 3/8" off and then later trimmed a little more. Great, things are moving along....but wait it can't be this simple.
After checking the fit of the plate I clamped the air box to it and attempted to mount the cowling. Yes, attempted. The carb sits to the left side of the cowling and there wasn't sufficient room for the box. It was hitting the side of the cowling. A little research laterI found and copied a solution from an RV-8 builder in Italy.