Help me do the math. 4.88 gears

The formula I used shows vehicle speed of 108mph at 7000rpm.
Are you sure you want to spin it this high?

BTW, I ran a combo similar to yours back in the early '70s with my 340 Dart Swinger. With a manual-shift reverse-pattern valve body in the 727 I was in 3rd gear by the time I got across an intersection.
Yeah it accelerated great but those gears will be a killer on the freeway - how do you feel about 4200rpm at 65mph?