A tad taller....
Your current tire (MU8516) is: 25.3" tall.
140mm/90% sidewall aspect x 16 = 126mm
126mm + 406.4 + 126mm = 658.4mm or 25.92"
So....that number is total height, that would affect final drive, but since you're already reading a tad lower than actual speed, the added .55" or half inch. A half inch will only raise rear ride height 1/4", and you'll see nothing different on your speed or mileage that's going to be even noticable.
“When the going gets weird, the weird turn professional....” ~ Hunter S. Thompson~
R.I.P. Rubberdown. 1971-2012
2005 E.G. Classic
Baisley Oil spring
Rinehart 3.5" pipes
S&S adj pushrods
3 stickers, adding 5 hp each. I swear......