Reinstalling my jet pump on my 1996 Challenger and had been waiting for a ring which the dealer stated was on back order but now says it has been discontinued with no further information. This ring is shown on the parts diagram going between the neoprene (foam) seal and the ride plate. Does anyone know if this ring is needed or is just the foam seal okay? The boat had bad cavitation before and I don't want this to happen again. Any help is appreciated Thanks.