http://www.gmpartsdirect.com/

Aight...I know the early LS1's have crappy slave cylinders. As far as fixing the problem, I've heard of replacing the cylinder or doing some kinda of drill mod. I'm leaning more towards replacing it. Only problem is, I found 2 different part #'s for the GM slave cylinders. Does anyone know which one is the better one?

15046288
or
12565145 <-- I think it's this one, but not sure.

Also, if I was going to upgrade the slave cylinder, would it be a good idea to upgrade the master cylinder too? I'm not sure if these have design flaws like the slave cylinders? I don't really need an adjustable one like McLeod sells...but if there's a better GM version, is it worth it?