If I was you I would get a new one, I had a 283 that did the same thing. I had gotten to the last bolt and when I tightened it, it just diddnt feel right but I could get it fairly tight so figured it would be ok. About a month later that bolt came loose and took out every thing, belts radiator hoses and the pulley for my water pump. It sound like it has alread been fixed before so I personaly wouldnt take a chance with it. Check out ebay or check the junk yard just my 2 cent .