anyone using these yet? any dyno numbers

 

they just came out.people are still testing them right now

 

Don't want to change out springs just for 280's.

 

Change springs for what? Same lift as 272's, just different duration. I believe Buschur is running them now with stock springs.

 

Longer duration with same lift will equate less radical ramp angles and therefore decreased need for spring pressure. On the other hand, more duration will shift the rpm potential upward which means higher rpm which in turn may mean that you want more spring pressure after all.

 

That's what HKS says ?