Quote Originally Posted by PlayingWithTBI View Post
Here's a picture of the chambers in the Summit 162108 heads CDeeZ and I are using. From what I can tell, based on your link these are the newer "fast burn" style?

Trick Flow Chamber.JPG
They're a much better chamber design than many of the earlier heads. The spark plug is angled toward the exhaust port to reduce intake shrouding, the chamber walls appear to be slightly tapered at the intake valve to improve flow, and the shape of the chamber appears to encourage swirl during combustion. I would expect these heads to require less spark advance than most of the pre-80's heads.