If you have stock rear gears,your short shifting.
1st to 58-60
2nd to 88-90
3rd to 119-121
4th to 149-151
5th to 175-180
6th to the moon
These are withen 1-2 MPH depending on what rpm you hit each gear.
I hit 129+ in 3rd @ 7500 in the 1/4 with stock 3.45 gears.
Enjoy Safely
Pete