I was wondering if anyone has tried going to a 13/38? If so what did it do? A friend went to a 38 on the rear and said he lost 2MPH off of top end. Out of the hole when we raced it depended on who got the whole shot as to who was in front. I wonder if you go down 1 in front and up 1 in the rear if it would make a difference worth trying? THANKS