I've completed my conversion to 6" PVC and have the 4" flex hose and fitting available. They are USED but in reasonable condition. The hose and fittings are located in Bucks County PA (between Philadelphia and Trenton, just off I 95) and are for sale.
4" hose Two 10' lengths Two 5' lengths and some 30" pieces4" fittings One "Y" fitting Three "T" fittings
3" hose One 6' and one 3'Plus lots of grounding wire
trixie AT energytactics DOT com