Craftsman. I looked at the sears parts site, and the list of parts is paltry. I purchased a Freud sBOX8 blade set -- it seemed the two blades were at different heights. Sent it back to Freud - they said it worked perfectly, and my arbor might be worn. Can't find a replacement part...
Hi Dave...looked through your web site...VERY NICE...
When you install the box set, take a look at the outside blade and where it sits. It's possible that the blade might be falling into the threads. If so, the dado stack might be wider than the arbor (non-threaded portion) can handle.
If that is the case not sure you can do anything about that...the bore on the blades needs to be a good fit on the arbor shaft. Possibly a thinner inner washer might help...?
Is it possible a machine shop might be able to machine a new arbor for you with a longer shaft portion...?
...I'm assuming that's what might be happening, of course...
If you're shopping anyway, try Marketplace on Facebook for a used saw (Unisaw, Powermatic, etc...). There are lots of Craftsman on there and maybe one of them could be the same model as yours...?