If you have an old 14" Rockwell Delta, I am pretty sure I've seen speed reducers for exactly that purpose. Plus don't forget you'll need a different blade, something with about 24tpi to 36tpi.
BTW, one thing I would mention as an afterthought is that I have no idea how that Delta keeps filings out of its bearings etc and obviously that will have an impact. It's one thing to blow sawdust out. It's another issue trying to remove magnetized metal filings. If you use the bandsaw often for woodworking and it's reasonably new, I don't think I'd do this frequently.
