I noticed that my spring bumpers we all dry rotted and torn like others have showing on here so decided to replace them with the Timbrens that were mentioned on here. I couldn't find OEM. I also noticed that the rear shocks were leaking so decided to replace those as well. Decided to keep the springs because I was reading they could last a long time and they are expensive. So far so good, I can't really tell any difference, the van rides smooth like it always has. All the parts used are below and the total cost was around $700.
Timbren HROD2 Rear Spring Bumpers
OEM seats and mounts
OEM Rear Shock Dampers
Timbren HROD2 Rear Spring Bumpers
OEM seats and mounts
OEM Rear Shock Dampers