I have a 77 and had the same issue. The cushion was wore out and i couldn't find one. I fixed by wraping some rubber sheet around the tube so it sits tight in the cushion / receiver. I glued it on once i got it lined up and it looks factory. Cost $6.
low rider
I only had enough time to get the front done on a 4" HFS install. The 77 40 is looking like a low rider :grinpimp: ... near draging in the rear with the stock springs.