Tranny question--maybe?

[Huck]

MY 71 truck turbo 350 is slow to engage when it's cold. Can take like 30 seconds before you get any action in either forward or reverse. Is this a factor of old fluid, dirty filter, or other more discusting problem? It also is not the best at downshifting when you push the pedal to the floor. If you manually pull hte shifter into second, it is just fine. I did check the vacuum line to the trans and it seems ok. Thought's, idea's, experience's, guesses??? Thanks---Huck