WANTED Detroit 8v53

Greetings All,
I have a 1970 41C I have been rebuilding it over the last few years and done quite a good job if I do say so myself. I rebuilt the port engine last year and thought there would be zero problems, come to find out I went to start it this Spring and very unfortunately it is SEIZED !!!!!!!!! Every boat owners worst nightmare, at least on land. I am in need of a Port Side 8v53 N Detroit Diesel ASAP. If anyone has any leads on one I would really appreciate being pointed in the right direction.
Thanks in advance,
Patrick