In top gear (0.86:1) it should be running like this: 1000 RPM = 45 MPH 1100 RPM = 49 MPH 1200 RPM = 54 MPH 1300 RPM = 58 MPH 1400 RPM = 63 MPH 1500 RPM = 67 MPH 1600 RPM = 72 MPH 1700 RPM = 76 MPH About the same as running a 3.42 rear with 22.5 low-pro tires.
Depends on what your running for power if you’ll like it and what roads you run. 80 mph is 1500 dead on the money in high gear. 9th is 1:1 so your looking at 26 percent difference that’s a big jump