My ae86 has a open diff and I want to change it to a limited slip whats the best way i could go about this? I understand finding a stock one would probably be best, but Ive found some cheap aftermarket ones on ebay. Just wondering if you can put an aftermarket lsd in a open diff housing and what things I might need, thanks

1985 gts... An early model aka zenki.. Oem or after u will still need to have them install . Mean u will need to remove your ring and pinion and transfer that to your new lsd. That my friend u need to have experience with or knowledge of how to do it right..
But back to Post topic .. If u have an zenki diff.. Then best is buy zenki lsd aftermarket ... If u want trd. I dont think they make the zenki any more but kouki is still available.
Kaaz tomei and some other brand... Trd how ever u need to cut/chop about 5-8mm off the tip of your open diff zenki axle to fit it... Unless u have an zenki lsd axle already... If that the case no need cut. Because stock lsd axle are shorter than the open diff .

Replace all seal and bearing while u are at it...
I buy the part and pay a pro to do it...

Hope that help

Ok thanks yeah that does help, so my rear end is completely stock open diff. Does that mean that for any aftermarket lsd i need to cut it? Or have it cut? Or is that just the trd

Ok first you need to find out exactly what axle you.
I know of a guy local here who bought an ae86 .. Which in the registration and title said is a 1985 toyota corolla gts ... Suppose to be a zenki?? Yes... But remember these corolla are over. 25 years of age and over time people swap out these parts..so this guy find out the hard way. He order a zenki lsd just to find out his car has a kouki axle sitting inside the rear end axle housing...
Ok here go to this link and do some reading this will help understand more.

http://www.dreamsofdrifting.com/ae86/axles/index.htm

Trd lsd is the only aftermarket lsd that requirer the lsd axle that i know of...

Best thing to do before u buy the lsd is to ask the seller about..
And remember to find out exactly what u currently have first.

Good luck

ok thank you