Our 416 has seen 9000 with out skipping a beat. Sounds like you have a valve train issue. We run a billet with a digital 6 and a 1050. Check all your grounds get race plugs and a coil that is 6 and 7 approved. MSD 8251 MSD Ignition Coil - Pro Power HVC - Red
The challenge I am having that it may be a valve train issue, is that I am getting the same 127 mph that I ran before the issue started.... So in other words, I am not loosing that much power.
