I am glad to know what it is,the shop manual calls it a 3.03 and nothing else and I have the seal in and most of the vibration is gone. I put what was supposed to be new rear drums that came off a parts car a couple weeks ago and they are terribly out of round but I have some comming from advance auto parts I ordered on line,I would like to know how drums could get out of round just sitting on the garge floor as I drove the parts car a little and dont remember them ever being bad. Someone I work with that did suspension work years ago told me that out of round drums will cause a vibration going down the road due to them beingb out of balance and its getting hard to find anyone to turn them so I bought new ones. Jeff