Engine ID help

Can some one help out with the ID of this motor.

 

Nailhead Buick

 

Yep, Buick Nailhead. I'm guessing '66 or older.

The way the valve covers sit horizontal are the big clue to identifying a nailhead. Also the the unusual spacing of the exhaust ports is another clue:

O-O----O-O

 

Not common to see one with manual transmission setup. Most were churning a DynaFlow. I believe that one is a 322.

 

Dude, you find the coolest stuff.

 

***uming that it's factory, those are '53-early '55 valve covers, and the flywheel is 322. The '54-'55 264 manual flywheels used a smaller clutch.