[lumpy3339]

Hello All, I am currently saving to build a ERA 289fia, I am also keep a watch for parts that I may need. I have come accross a 1987 xj6 IRS, it is still in the car. My question is what should I salvage? I will be going with the ERA design IRS. Also how would I go about determing the gearing and if it has posi, any place to look for markings or numbers? thanks Jerry