Q Code 351 CJ value?

I hope I'm posting this in the right place. If not, admin, please move it accordingly.

My Dad has a '73 351 CJ Q-code engine out of a '73 Torino. Someone is wanting to buy it from him and we would like to get an idea from the experts about what its value is.

Its been rebuilt, bored .030" over, mild cam, stock intake & carb. It has 4 bolt mains and 4V heads.

Any info will be helpful. Thanks in advance!