As to jetting, it's best to change one thing at a time. Use the 30 pilots, it should help with starting. Then after you get air screw adjusted see how it runs and or plug chop or "read" the plugs. My son's 'shee has FMF "Signature" pipes (early fatties) 310 main 27.5P, 70+*, high humidity, 1000' elev. Might be tad rich but it's better to leave a horse or two in the barn than to leave a hole in your piston
Try the 320 again, does it not run good with it? Go down one size at a time.