I'm a little curious why you are so worried about the output of your radio
on ssb.  If you're running 90 watts or better with full carrier, chances
are, unless there is some drasticly wrong, you're running what you should
on ssb.  Unless you have a good scope or a good peak reading meter, and a
two tone generator set to the proper level at the mike jack, measurements
are pretty much meaningless.  You're dealing with frequency response of
the pre amp, microphone itself, and other states before the audio is
converted.  I have an ifr service monitor with a peak reading watt meter,
and on voice or a single tone, it just isn't that accurate, and it cost
over seven thousand dollars.  If you want an amp, get an amp, but I
really don't think there is a thing wrong with your radio.
73s
Butch Bussen
wa0vjr