Rear end chatter - 88 vert
 

Have an 88 vert with 70K miles on chassis and a rebuild with about 20K on it. A couple of months ago when I first got the car, there was a chatter when starting off in reverse, now more recently, when starting in first gear, I also get a rear end chatter/shudder. I don't belive this has the LSD, so I don't think it's that (found that info when searching). Any idea what it would be since it didn't always do it in 1st gear?