I've been using a Brazetek plate chiller since 2008. Put it together with some quick release stainless steel connectors. CIP with hot PBW circulated with a March pump. Hob blocker on the boil pot. No probs.
Buy an inexpensive thickness gauge from your local auto supply store. Read up on the milling blogs on what the gap is best in your area. Before your LHBS grind your grain have them check their gap with your gauge and have them adjust it to your specs. Voila! Consistency in your grain...
Walter,
Part number 0809-0107-0200 being 2.156 Dia. Do I need to change the cover and housing as well to accommodate the bigger diameter impeller or can I just change the impeller and use the same cover and housing?