my 12.47 runs were at 75 and 79 degrees. I also cannot figure out whats up with the 60' because one of the 12.47 runs was with a 1.855 60' and the other was 1.98 60' I still cannot get a constant 60' but the drag radials have helped. Usually between 1.95 to 2.05 Have you adjusted your clutch? If your grinding maybe set it so it grabs a little higher? Later, John