Posted by Kev on 6/26/2004, 8:38 am, in reply to "Re: 400 or 455"

It looks like the date code is June 11, 1965. The 9778789 part # is a 1966 389 block. There should have been a 2 letter code on the front of the motor. WT, WS, etc. something like that. That will tell you a bit more. But it looks like you have a 66 389 my friend. Kev