finding a posi differential for 1990 240sx

An infinti j30, or a nissan 300zx but check the number of bolts on the axles.

go with the j30 there sitting everyone in junkyards. i dont have the link but i think there is a writeup somewhere on 240sxforums.com.

its not called posi, its called Limited Slip Differential ( LSD ), you can get one from a Q45, a S13 Silvia or 180sx ( JDM ) OR... a S13 SuperHicas ( its a US model, hatchback.. it comes stock with LSD )

not trying to flame but the s13 superhicas lsd would be damn near impossible to find and a jdm silvia or 180sx one would be way to pricey. call up your local junkyard and go with a j30 its a direct bolt in except i think you have to swap over the diff cover but im not sure. do some research.

i have the same question but what year of the j30 would fit or is there only one