RPM limits of GM computer/ignition module?

[Christopher Bennight]

    Have a friend with a solid roller 400 LT1, and regardless of computer programming 
can't seem to rev over 7000-7100 rpm - it basically feels like a rev limiter is hitting
in that range.   He is using an '8051 95LT1 pcm - tried rev limiter values from 7500
to 9000 with no difference, so we are thinking it's hardware related.  (Car has a
msd digital 6, rev limiter there set at 7500).

     Some people have indicated that it may be a problem with the stock computer -
 though Ed Wright says that they have had cars that would turn that high on the
dyno with the stock computer, and he thinks it's opti-spark related.

    The best hypothesis I have heard is from an individual who believes it's
ignition module related - and that starting at 6800-7000 you get horrible
spark flutter and the unit just isn't reliable anymore.    IF this sounds correct what
kind of aftermarket units would interface with the opti-spark?

    Thanks again for your help,
    Chris Bennight

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