I’ve purchased a 36-812 (30″ B fence) unit that was built in the early 90’s.  This has an interior angled ‘deflector’ to direct dust to a slot that runs the width of the base and is, maybe, 3″ high.  I figure I can either cobble something up to that slot with a 4″ port aiming out the back, or just cover the slot and put a 4″ port in the back of the base.  Thoughts/suggestions? 

Oh, did I say I was excited, LOL.

Thank you!