Hey Chief Delphi,
I made a mistake early on in the season when ordering parts and underestimated the number of 3/8" hubs my team needs for our design:
http://www.andymark.com/product-p/am-0134a.htm
AndyMark is out of both of their 375 Key Hub versions. Obviously this is a popular product this season. I've looked at a few other websites and can't find any comparable products that are available. Are there any sites that you know of that has something like this?
Worst case scenario, I know we can change the shaft size and use different sized hubs. However, we've already invested a decent amount in the proper slotted rod, pillow blocks, and other things that would work for 3/8" shaft.