The way I do 60-100 is to try to replicate what the technique would be if tested according to the protocols used in the various car mags like Car and Driver, Road and Track, etc. To do that you have to assume that it is an actual launch from a dead stop, like a drag srip launch, but you actually begin the run up in 4th gear slightly above 3,000 rpm. Go WOT there, so you are acutally cooking on full boost well before you get to 60 mph. Then be ready to hit the start button on your stopwatch as your speedometer needle hits 60 and then hit it again when you hit 100. You can experiment and see if you want to hold it in 4th gear, or make a flat shift into 5th at 6,000 rpm. It works out about the same for me, because the time to make the shift cuts the benefit you get from getting back into the fat part of the power band. Try it that way.
My G-Tech Pro RR accelerometer produces identical numbers to that technique, but does require a full launch from first gear to data log and produce the chart. BTW: The better car mags who have automotive engineers doing the testing typically use digital accelerometers to gather the metrics rather than drag strip timers, which could not give you all of those intermediate time, speed, distance intervals. The accelerometers they use are a bit more advanced (and more expensive) than the current generation G-Tech i use, but the results are very close (usually within one tenth of a second). A good acceleometer is an excellent tuning tool, iMHO.
A pure stock gen 1 would typically cover that speed interval using the same technique in the 7.7-8.0 range depending on conditions. A gen 2 similar but maybe a tenth or so slower. Hope this helps.