First lets start with I have a second gen jdm b16a with a y21 trans with lsd and hydro. Im a little confused as to which throwout bearing I need. Can I use the one outta the 99si?

 

A throw out bearing should come in your clutch kit, unless you are parting it together. A 99 Si or 94 del sol DOHC bearing should work fine.

 

Thanks for the help and speedy response. And you nailed it I grabbed a competition clutch kit that the kid just used the throwout bearing from. Not so sure as to why but hey I gotta great deal on it so I figured it was worth the throwout bearing purchase.