gear change....possible gain?

i run 4.10 with 28x9 and my tacho shows 6000 over the line
my 60's though are a bit less than yours, @1.65 but its nearly the same, but i have the low first gear in my trans,
personally i think where you are right now is right, and as others have said altering the gear and height could slow things down a bit
i would put the 4.10 in :)