This is the hose going through the 3 1/2" hole drilled through the frame, upper and lower. I will weld in a tube as soon as I can locate one. Right now the hoses are joined with a 3" piece of PVC. I may just use Industrial epoxy and let it go at that. Make sure when you use the hole saw to drill through the crush zone, that when you drill out the bottom there is an AC hose about 3" under the frame. Leave enough of whatever pipe you put through the hole to attach the hoses.