mole and hotrod are right,
the maximum input ratings that rmitaly publish are nonesense,
many people over here interpret rm's ssb input ratings as avg input pwr,
heres what happens on a stock klv550 if you listen to rm and input 10w fm,
i see rm amps MUCH more burned up than this one, fortunately this one was only ever run on pwr setting 6 so the input sellector resistors and board did not get fried,
http://i5.photobucket.com/albums/y152/ukmudduck/burnt feedback resistors/P1010207.jpg
you may think that if you input 10w and use a lower pwr setting on the amp that will protect the amp, not so, all you get is burned resistors on the pwr sellector board and 6 settings that all produce full power,
take rm's figures and half them, treat the ssb input rating as pep, you will be in the ballpark of what a stock klv550 will stand without burning components,
if the grant is stock output it will be about twice what a stock klv550 is happy with.