904 auto. trans. wont shift into gear?

[sm73charger]

Hey my 73 Chargers 904 Automatic Transmission has been leaking fluid for years now because I havent driven it and the other day I went to back in out of the garage but it wouldnt go into any gear. I checked the fluid and it was almost completey out so I put almost 5 quarts in and ran it and tried it again and the shifter shifts into gears, but the car wont move. The parking brake is off, so I dont know why it wont go in any gear so I can move it? Any thoughts?
PS its been sitting in my garage for 8 years just now getting to work on it.

 

[dryheat]

Let it idle for a while in neutral ... not park. Hopefully the pump is working and will fill it back up.

 

[383man]

And recheck the fluid level. Make sure you check it in neutral with the eng running on level ground. It may have lost more fluid then 5 qts because the converter can drain into the pan when it sits and the trans can hold atleast 10 qts. After checking the fluid run the shifter through all the gears and back to neutral and then recheck the fluid level. Ron