I'm going to start a build of my 90 XJ soon. I have a bare mid 90s HP D30 housing that will get 4.10 gears. I also need a right side one piece axle shaft. My question is, are the knuckles from an 87 HP D30 able to fit the 90s housing? I realize the brakes and unit bearings are different, but are the knuckles interchangable? I actually have a buyer for the 90 D30 I'll take out.