Help, 1987 shortie cruise, convertor, and speedo ?'s

[nico]

I recently bought a 1987 short wide fi350 700r4 and have been trying to diagnose a few problems with it. First is the speedometer, it reads about 20-25 mph slow. I can be humming along passing people on the interstate (normally around 75) and the truck shows 52-55. Second is the lockup convertor not working? And third is the cruise doesn't work, I have replaced the rotten vacuum lines and tried to adjust the slide linkage to no avail. Any help would be appreciated, and i will post up some pics soon. Thanks Kaysen