I was running fully loaded with the bolts and washers at 8-9lbs on a 09 twisted 2871 and running 8150, with a 36* and a 36/44 didn't really stop the rpm but created more belt heat and anything over 9lbs I didn't run a 36* because I crushed the rollers with that much pressure on them. My dealer ran 36/40 on bd kits and they worked really well. But at lower elevation I would prob just run a 38 or 39 and get the plates
You can also run a softer spring, that might be the easiest fix