I had a "dash pot" go bad,on a '65 G.M.C. pick-up I had. That caused the same problems as mentioned.(It also had the 2-speed "Slush-Box"). There are a couple of "vid's",on "Youtube",on how to "Straighten-out" a warped Roch."B".(Make sure all gasoline is evaporated,before attempting to heat halves with a torch)! Mine was warped,and I was lucky enough to find a "freebie".
