One of the issues I had become aware was that was a harmonic problem (ie instability at around 7850 RPMS), and an additional problem with the hydrolic lifters collapsing at 8200 RPMS or so. But then again not alot of people actually ever ran must more than 7200 RPMS so what shows on a test bench may not be real life results and etc. Also you had some work to your heads so that maybe your saving grace . Go rev it upto 10K next time let me know how it holds up :-). Or not I am sure your turbo dies off way sooner than that anyways, which becomes a mute to ever having a higher RPM band.
