Voltage, and drop, is easy to measure. Amps are much more difficult without a good inductive amp meter. Especially in the 1,000 amp range!
I tried the fancy geared starter that cost a ton, it cranked to slowly for my taste. Back to a stock Ford OEM NAPA starter (50 bucks) and it works just fine. I sure wish I had taken amp readings before and after with those two starters (just for the heck of it).
Dang, I'm tempted to go out and buy a clamp-on ammeter that will work with my Fluke-87.
In fact, I may not only do that, but also rig up a short cable to the starter (solenoid actually) to compare amps to my trunk mounted cable setup!