OK I finished one side.
Full Size pic at
http://www.priveye.com/duct/four.jpg
http://www.priveye.com/duct/three.jpg
Here's what I did:
1 intake duct from Racer Parts Wholesale = 15.95
2 3" to 2 1/2" reducers from Woodworkers Warehouse = 3.99 ea
10' box of 2 1/2" hose from Woodworkers Warehouse = 10.95
2 hose clamps = 1.00 ea
some duct tape, rivets, 8-9" of flat stock, some silicone/glue/epoxy
More details upon request,
Roscoe