<VV> POWERSLIDE PROBLEM

[N2VZD TIM]

I probably will end up taking this one back out , at least it is my own truck. @5 years ago I rebuilt a rare 64 FC powerglide for myself. It has been on the shelf  waiting for install. I have installed it in the truck. First clue that a problem was looming was fluid did not want to go down the fill tube without burping. I cant get at the vent to check it other than the cap spins. I have forward speeds in all positions of shift lever. Low stays in low , shifts up in drive ok , still forward in any position of lever. I removed the vacuum line to modulator to boost pressure , still have the problem. So some valve stuck or something missing somewhere. Only other clue was I had to readjust the TV valve with the tool .Ideas ??Regards , a very tired Tim Colson  C N Y C C