As the video shows the a/f is on the lean side for max power should be 11.5 to 12.0 then you need more timing 42* to burn the fuel at the correct time.
I would lock out the timing and see what happens, I think it would help.
With the lifters so tight I think they are pumping up and holding the valves open at higher RPM, call Comp. or whoever the cam is from and ask what the setting should be, usually a 1/4 to 1/2 turn.
The cam looks good as is especially for a turbo.
