Motor head and block ID

[leekvanli]

I have a 1963 Pontiac Bonneville with a muscle car motor in it I am trying to ID. The person I bought like it from thought it was a GM 1972 455 block with a GM 1965 389 heads. I talked to a motor builder in town about this possibility. He said that combination would no fit together and it would build up too much compression. It also has a tri-power set up with three two barrel carbs. I would sure like to ID what I have. Any thoughts?

Thanks for any info.

Lee

 

[leekvanli]

follow up to 63 bonne ID post

here are some pics

 

[melsg5]

yes, everything is based on the codes you find on the block and heads. Rather than try to write a long response here I will direct you to Wallace Racing which has charts of all the heads and blocks that were made.
http://wallaceracing.com/engine1.htm