No 3rd gear

[absolutezero]

Hi, to all. Well heres whats going on. I have a c-4 from a 64 falcon (5 bolt)
It has 1-2 fine auto and manual shifts, but it will the just wind out 2nd, even
manually. its got correct full fluid. it has been sitting for a couple years before
i bought it. so any ideas...anything

thanks