tranny issues

[oldstyle69]

I have a question. First of all I am new to the board this is a great site. I picked up a 72 seirra granda last night. I love it. It is very soild for a Iowa truck. I do not have much history on it but it looks to be about a 10 year old restore. 400 motor 400 turbo, posi, factory air, tilt rallys,tach. I got it running tonight it had been sitting for a couple of years. It runs very nice but the tranny is sluggish going into reverse. When it does engage it slips. It seems to 75% of the time miss first gear completely. Starts in second gear. What do you guys think? I was thinking maybe some stick Valves in the body. Is there a quick fix? has anyone ran into this issue before.