[kettbo]

The 289 block has a pretty good reputation
Even if it is .060-over...there is room for another build or possibly two
The mix and match heads are not a plus
For $200, I be on it....

 

[kettbo]

My #289 late 72 casting is indeed a 4-bolt.

The 010 and 020 markings on SBC castings....more tin and more nickel if present
And I'd almost swear my #289 block has these marking too but I'm not gonna tear my engine down looking!

 

[kettbo]

see the pics in FRYNTYR's "BBC INFO" post, top of the page in ENGINE FORUM