65' Won't Go

I just finished my 5-lug conversion on my 65' coupe. This included lowering the front about 1.5", and lowering the rear about 1". I also had to have my original 6 cylinder driveshaft modified so that it would mate up to the new 8" rear-end. Got everything bolted together this weekend, pushed the car out of the garage, pressed the gas pedal, and noting. The engine revs but it doesn't go anywhere.

I pushed the car back in the garage checked that everything was connected, and tried again. Nothing. Jacked the car up, and re-adjusted the transmission selector. Everything looked spot on. Decided to test everything with the rear wheels off the ground. Tires spun perfectly driveshaft rotated everything looked good.

Lowered the car back to the ground. Pushed the car back out and nothing, wont go anywhere. Checked to see if the driveshaft was spinning its not. Does anyone have any ideas here what could be wrong?
 
The transmission level shows full. When I changed the driveshaft I drained the transmission about 4 quarts total came out. I changed the filter then I poured type f in until it showed full, then ran the car until it warmed up. Added another 2 quarts and it shows safe. Sorry I don't know much about transmissions. How can I tell if the Torque Convertor is empty or low.
 
Just a thought......

Get the car in the air with all 4 tires off the ground, have someone in the car changing the gears while you beat on the transmision and pan with a rubber hammer, if its a stuck valve it might break it loose.
 
So a valve could be causing this issue? I looked under the car and my drive shaft is showing about 2 inches between its u joint and the tail-shaft of the transmission, could this be causing it? Its a c4 by the way
 
What was done to modify the driveshaft? With the selector in park, try to turn the drive shaft. If it rotates, something is wrong with the yolk not engaging the splines on the output shaft.

Otherwise I'd have to agree with the other guys on the fluid low, or empty torque converter.
 
The driveshaft had a new end put on so that it would match up the rear end. The rear is from a Ranchero, so I converted the end of my driveshaft to match.

With the selector in Park the driveshaft will not rotate, with it in Neutral it spins freely. So I figure it is engaging properly.

Sounds like it is the Torque Convertor as well. From what I have read the pump in the transmission will fill this continuously. Is this correct? If so I can bring the transmission up to operating temperature and continue to add transmission fluid correct? About how many quarts should the transmission and Torque Convertor hold? Its a early C4 transmission by the way.
 
Sounds like it is the Torque Convertor as well. From what I have read the pump in the transmission will fill this continuously. Is this correct? If so I can bring the transmission up to operating temperature and continue to add transmission fluid correct? About how many quarts should the transmission and Torque Convertor hold? Its a early C4 transmission by the way.

Yes, the pump is supposed to fill the tq converter. There's no special fill procedure for it. Just let it run 'til warm, shift through the pattern slowly a couple times, put back in park and check the level. Add just a little at a time and repeat until at the full line. You should be able to feel when the torque converter starts to work in drive and reverse.

When I had my C-4 and my Stang sat for a couple weeks it would do that sometimes. The fix was to simply wait and eventually it would be fine. If I added fluid, it would help, but when it got up to operating temp, it would puke out the dipstick. I suspect crap in the fluid kept a check ball from sealing, which allowed the torque converter to drain into the pan.

IIRC the capacities are:
Tq conv @ 3-4 qts
Pan @ 3 qts
Completly dry, total 12-13 quarts