i've been trying to figure this miss out for over 2 years...
its misses around 5900 and up.
i've changed opti's twice, plugs 3 times, wires 3 times, valves springs, lifters, 3 different coils, unhooked igniton box... i know i've done more but cant think of it now.

here is a dyno graph of it

http://home.earthlink.net/~blkchevyz/dynosmall.jpg

i also have a data master file of this dyno run i can e-mail.

 

I am far from technical, but is there a rev limiter that could be kicking in? Like a MSD or even the stock PCM?

 

i've checked it a couple times, i have the stock one set at 7000 and the accel is set at 6800 or so. i have tried running without the accel and it still missed.