Hey fellas, I have more of a curiosity question vs a help question. The 68 bird I bought last year unfortunately, doesn't have the original engine. It does however, from what I can tell, have a complete 68 gto 400, with #16 heads. It runs really well but needs freshened up. It smokes a little and starts a little hard when warm...... Maybe a timing issue? Question is, if I remember correct those #16s were like a 10.5:1 compression, so I would think it is safe to say someone has adjusted the compression to meet today's fuel supply? I can't see that the head gaskets are any thicker than normal. I started out at a rolling 20 mph in 4th gear, and gave it all she had and could hear no detonation. Is it possible being that old that it doesn't carry such a high compression due to worn rings, and is doing ok? It is a 4 speed car with 3:55 rear, so that would maybe explain the awesome pull it gets. Then again, it's been a long time since driving a high torque pontiac 4 speed. Thanks guys.