I have a basket type blade guard on my contratcor TS (shop made). It is about 4"wide by 12" long by 4"high. I'd like to add dust collection, which would come off of a 4" main pipe and run only about 4 feet to get to the guard. The the junction with the main pipe would be only about 5 feet from the DC iteslf. I already have 4" collectoin under the saw, which works well. The 4 foot run from the mainpipe to the guard would be all flex hose. Would a 1" hose to the guard be sufficient? how about 2.5"? If I add 2.5", should I reduce the under-the-saw connection from 4" to 3"?

I use zero clearance inserts. The only time that above-the-table dust is much of a problem is when I am ripping and one side of the blade is exposed (i.e. ripping off 1/8" or less). But it can be quite a nuissance when doing these cuts.

Thanks