[67_C-30]

Originally Posted by Skirkpat

The diference is the hardened exaust seats, not the appearance, while I have not ran Vortecs and have not had experience with the two castings, I am sure the difference in performance would be minimal if even noticable...but there is a difference.

Yes, there is a difference, but there's no reason to avoid the 906's. That's all I was saying. Both are great heads. If anything, the 906 would be the better head in terms of durability while still performing great. That's why dirt trackers love the 906.