So why haven't more people used these heads?
They may not make the most power but, they still make a ton.

I have a set but never used them because back when I got them 6-7 years I knew nothing about engines (still don't) and figured they would be the last set of heads I would ever need.
I eventually realized that they are way overkill for road course use.

They are a great set of heads but too bad more people never utilized them. I often wonder how far the Predators development would have gone if they were the popular head option?