engine date code help????

[ace13733]

Alright I bought and 84 Chevy k20 off a guy it has a rebuilt 350 come to find out the vin of the truck says it was originally a diesel so I've been trying to figure out what year it is I've checked the ledges on the back of the motor above the trans there is only one number 14010207, that's on the driver ledge the only other number I can find is on the side of the block and its cfd 207 and from what I understand that # means central foundry division casting 207 and help would be awesome?

[geezer#99]

Look here. It's a 80-85 350.
http://www.mortec.com/castnum.htm