What's the deal with the Poly 318

I haven't found anything off the shelf to fit that carb spacing. I will have to make my own from a pair of air cleaners later. A little cut and fit.

oem ones are plenty rare and pricey. I used to seem them occasionally back in the 90's when I went to Nats and Carlisle, back when some folks had some real rare parts to hawk, not used steering pumps, and alternators!! ha