I use the 11/32" emission hose. I get mine at O'Reilly's Auto Parts store. This size also replaces the PCV hose. The package comes with enough to do both. With this size you don't need any clamps to hold them on as with 3/8"hose. Bed sure to adjust the balance tube so it lines up with the one on the head before you put the hoses on. Cliff Nieman Oklahoma Corvair