Tom, Back in the 60's I had bolt in dividers, and they were held in by the pipe plug at the top. I made a washer about 3/16 thick with a slot in the bottom of it to hold the divider, it went in first then the pipe plug. But my dividers had a wing shape that flared out, back in the bowl area and this helped to hold it in place, the pipe plug and washer just kept it from falling over, worked very good.
As far as air speed I need more info: cfm@28" cam lift cross section area
