Mid range bog on 05 M7?

[powerstroke 350700]

The sled comes out if the hole good then bogs and berbles at 6500rpm if I just flip the throttle a few times and it will come out of it or it will eventually come out of it holding it wide open? Any ideas its a friends sled he is going to clean the exhaust valves and try that. Also on these sleds do the exhaust valves have two slages, mid way open and all the way open or just one stage all the way open?
Thanks
Ryan Hajek

 

[JoeySlushr]

Mine was doing that. Chased it for a year. Found a cracked reed petal with a bore scope down the throttle bodies