Done shims and spring. Now what?

Hi!
I have a 2011 grizzly 700eps. 26" maxxis big horns. 1.5mm shims ,purple spring.

Use the atv for trail riding and towing moose in the hunting season… So i need it to be slow and strong when towing.

I’v heard when installing a new spring, i also need to change the weights? Heavier?

Is there a method for finding the correct roller weight?
Do i need new weight?
What will be the new feeling of the bike with new weights?

Runar