No, the variator affects mostly the acceleration. Your top speed will be the same. Only two items affect top speed (1) unrestricted CDI which allows higher RPM, up to 9,000 RPM compared to 7500 RPM for a stock unit, and (2) final drive gears. It takes a few hours to swap the final drive gears, but you'll get a good 10% increase in speed. Both items together will get you almost 50mph. Just remember, riding at 9,000RPM is hard on your machine, and its service life will be shorter. On the other hand, 50cc crate engines are cheap on eBay (about $250), so the price of experimenting is manageable.
