I use GM Synchromesh in my 92 GSR. I started using it because I had a nasty grind in third. It got rid of the grind pretty much unless I am gunning it. I don't know if I like it tho, lol. Ever since I got it my gas mileage has been slightly decreased and my tranny has been acting funny lately. I don't know if my tranny would have done this stuff anyway, so its hard to tell. It works great at first, but after a few minutes, it gets really sluggish at about 3.5k RPM and just in general acts weird.