What gear for 6K in 1/4 mile?

Im running a '26 slick on my Dart and im running 4.10's.My motor is a 10 to 1 408 stroker with about the same cam you have.Mine is .484/.510 with 230 duration and its done at 6000 rpm.I run 11.40 flat in the 1/4 at 114 mph and go through the traps at 6200-6300 .I think my car would run a faster with 3.90 gears ,but havent tried it to confirm ...