By the book, you should vary the speed and don't exceed 75% of redline for the first 500 miles. For the second 500, vary the speed and ease it up to redline occasionally. Accelerate WFO in case of emergency only.
Considering that the gearing puts the redline in top gear at around 108 MPH, there should be no problems running at up to 75 as long as you don't hold it there for long periods.
