here we go.... Went to replace the pinion seal today and wow what a day it turned into. by the time I had finally gotten the pinion seal out and was ready to put the new one in, it did not fit. Thinking summit racing had screwed up my order I called and was assured I not only got the right part but that this seal did indeed fit a stock 70 skylark. Not only did they not look exactly the same ( the one I pulled out had a flared end) but the old seal is 4mm smaller than the one I was trying to install. After talking to someone from tech there he came to the conclusion I must have had a rear axle swap at some point in the life of the car which is entirely possible since I am the third owner. heres where it gets interesting. from all the searching on the internet I can find the bolt pattern and diff cover are that of a 8.2 or 8.5 Buick rear axle which both take the seal which I had tried to install. So I guess here is my question..... What could I possibly have in my skylark that looks like a buick rear end, but has a pinion seal which is 4mm smaller than stock (overall diameter 2.36 inches) Not sure where to go from here. any suggestions?