Josh,
I removed the 4" adaptor and built an MDF shroud that fits completely around the outlet of the blower, it seals against the yellow housing. I did it on mine not because mine was slowly filling the interior with fine chips. I tried everything to amend that issue first but finally realized it was a tiny leak out of the plastic blower housing.
It works fine with a 5ph clearvue, not as well with a 2hp roll-around collector. I've had to make due with the 2hp collector while building a new shop.
I've found the plastic blower part of the 735 to be the true weak link in those machines. I had to replace the plastic fan when I bought mine (used), and I've had to use judicious JB weld on the housing (which cracks at the 3 mounting posts).
Great machine for part-time, weekend, or portable use!