rear end gears

once again I am in search of answers from the ones who know! changing the rear end gears in my 1996 Z28 lt1 bored .30 over with comp cam

305, K&n cold air induction with granatelli mass air sensor, borla exhaust, 160 degree therm with custom programming .....I have a six speed with 3.42 in it now.... the question is........3.73 or 4.10 to replace the 3.42? its not a daily driver...take it out on nice days and I do not go far with it (longest drive taken is approx 90 miles) baby it most of the time!(except when mustang needs to be taught a lesson)are the 4.10's to much? at 75 mph in 5th im at 2800rpm, in 6th at 75mph at 2000rpm...idles at around 1000 rpm if that helps..thank you in advance for the help!! as always!!!!