Before you choose a pad based on weight you need to determine the center of balance (CoB) as well as determine what your preferences are reference gun balance. Experimenting to determine what your preferences are can get involved. Note that the CoB is just part of handling dynamics equation. Others can better enunciate on the various factors than I.
As noted by previous posters heavy rubber pads can significantly effect gun balance. Use of lightweight microcell pads can be a good alternative to heavy rubber pads. They require a title more care and the correct grit sand paper belts to install.
A source for such pads as Tut notes include Hastings
https://www.hastingsdistribution.com/index.php?l=product_detail&p=60With some effort they can be found in black, brown, and red brown.
A side note on center of balance, rather than express it in terms of the hinge pin, I find expressing it in relation to the forward trigger on your gun is more useful. I have found my side by side preferred CoB around 3 3/4 inches in front of the forward trigger.
