The answer is...it depends on you.
1) do you agree with the OEM's ratings and design paremeters?
2) do you personally have a problem with exceeding GVWR?
3) some go by the axle ratings instead of the GVWR which typically have a disparity and so they fudge the numbers that way.
4) some take the payload sticker as absolute
That all being said...nobody that says 'no you can't' or ''you shouldn't have any problem' are responsible for the safe operation of your rig...that's up to you.
IMHO...since you asked about 100 lbs that tells me you may be a bit iffy about this nearly or already overloaded rig. IMHO...the real question should be if it's time to upgrade the truck. The answer to that is again...up to you.
Thanks!
Jeremiah