Just because you go heavier does NOT mean you will gain any more top end speed. You may be at the max already. So to find out if it is possible to gain a couple more mph on your top end speed you need to mark your Variator and run it at wide open throttle and then see how much of a mark is eft on the Variator. If you have 1/4 or more of an inch left then YES you can wiggle some more out of your top end speed by trying to get the belt to climb about 1/8 from the edge of the Variator.
If the Mark left is already at about 1/8 from the edge of the Variator that is all she wrote. If you really want to gain good top end the best bang for your dollars is Taller Tranny gears. If you go 2Up and 2Down on the gearing you will gain anywhere from 6-8 mph depending on your motor if it has good power. Alleyoop