When I upgraded to a full float at first I bought new weld on shock mounts in order to reuse the original Fox shocks, but since I had cooked them twice I decided to upgrade to remote reservoirs to get more oil and cooling. Since I was getting all new ones I decided to just use the original mounts. Depending on the amount of your lift, you need to cycle the suspension to determine the proper lengths. First jack the van up by the frame until the tires are off the ground and then measure the distance from the top stem mounting point to the center of the lower mounting bolt. It's a little harder to measure the full bump length, but I measured the static distance with the wheels on the ground and then added the distance to the bump stop, giving me the maximum compressed length. Then I went here to find the proper length.
https://www.ridefox.com/family.php?v...+Top+-+Eyelet+
If you have difficulty finding exactly what you want, once you have cycled the suspension, give Fox's customer service a call.
What I later discovered was that there was not enough rebound dampening, and so I revalved them adding some stiffer discs and now they are perfect.