Have needed to do this for a long time for my mambas...I have 3 Model 600s(economy, 6 ft. long)....what diameter and size of PVC pipe do you use to block the upper and lower lips? These are 6 feet long models, should the length be slightly longer so they fit more snuggly? If anyone has a better method than the PVC pipe any suggestions would be welcomed. Thanks,
Drew.

