Well, your dealer is right about one thing, it shouldn't be pinging. Other than that they seem kinda disinterested.
Assuming that you aren't one of those guys that rolls on the throttle at 2000 rpms in 6th gear and complains of pinging, and assuming that the fueling is spot on then I'd say you have something going on
internally with the motor.
I don't think there is any "bolt on" things that are going to solve this. You shouldn't have to be adding fuel controllers and it's not like the timing can get out of whack.
Last time I heard of this it turned out that one of the heads was smaller by 6cc's thus bumping the compression up on one cylinder. Either that or you have a valve/carbon issue.
Get prepped for a pain in the ass if you have a crappy dealer. In the meantime no loads (roll-ons) on the motor under 3K rpms.
The Vic Shop, Inc