yeah they said there are two different ones for the 1.6
There are actually 4 different ones. There are 2 for each transmission. So, if you have a manual, there is a CA emmisions model (Which is direct drive), and there is a Federal emmisions model (Which is gear drive). It really doesn't matter which one you use. Even though I have a CA car, I chose the Federal one, as gear driven starters are more reliable and cheaper.
__________________ 1991 Sentra SE - Auto to Manual swap, 15" Rota Subzero's, 205/50 Kuhmo 712's, Tsuru headlight conversion, SE-R front and rear disc brakes, SE-R front and rear swaybars, SE-R throttle body, SE-R rear inner taillights, HS CAI and Header, H&R springs, Koni shortened struts, ES Hyperflex kit, B&M Short Shifter, Autometer gauges.
from experience, the gear reduction starter is the wrong one for a 5-speed federal emissions sentra. not only that, it was also considerably more expensive.
in case this helps you at all. when I worked at auto zone and needed a starter, I pulled it up, and under manual transmission, there were 2 options, direct drive and gear reduction. gear reduction was the wrong one. at least through auto zone. even still, my faith in remanufactured aftermarket parts has dropped severely after having to replace my alternator 3 times and my starter twice.