Advantage of doing the lower is you increase belt/pulley contact area. Also you’ll pin the crank while you’re there.
Problem with doing the upper is you decrease the belt/pulley contact area. Belt slip can occur but you’d need to be running a pretty aggressive setup or a super cheap pulley or belt.
Talk to your tuner about your goals and concerns, they will steer you in the right direction.
If you modify, be prepared for the worst case scenario and for the potential for FCA to void your entire warranty.
I agree with this, Not everyone will agree you will see what most are running and between that and talking to your tuner you will nail it. The harder you push it the less room for error. Bad gas maybe only off a bit but yet kaboom. Dont let me scare you though you have to talk with your tuner ask him the pros and cons .Just make sure you find a good tuner thats far more important then anything else.I’m sure it has in several people’s mind but they may not all agree. Lol. Have you searched for that chart yet? Different tuners will tell you different sizes because some are more conservative than others. There’s risk when you modify, so it’s more like how much risk are you comfortable taking. You could have a fuel pump issue at speed like I did and the more you have it turned up, the worse the results are going to be. Had I not had the issue, that setup I was running would’ve probably been fine.