My 71 8.5" 10 bolt posi rear end has loose spider gears and is whining at speed under slight acceleration. The bearings seem good so I believe it's a ring/pinion alignment issue. 4.10 Gears only have 1k miles on them and were completely quiet until the past 10 miles. After a little inspection I see that the spider gears move up and down about 3/16 but look to be in decent condition. Can I get thicker spacers for them to take up the slack or must I replace the spiders? Not sure about the clutches. A little research shows new spiders and clutches are 3/4 the cost of a new chuck. I am fine with a 10 bolt and do not want to start looking for a 12.. What have you guys done with your 10 bolts?