[77TA406]

Originally Posted by smittyseng

Here is what I recently did on my 74 t/a 8.5" 10 bolt. My stock axles were junk.outer bearings had cut into the bearing surface (before I bought the car). I bought new 12 bolt 30 sline axles for the same price as the 10 bolt 28 spline axles would have been,new outer bearings and a new 30 spline 8.5" posi w/400 lb springs and composite clutches. I also regeared the car at the same time but if your gears are good and the ratio you want it isn't neccesary. The axles were only about 200$ and did not have the weak looking factory taper either,seriously beefy compared to stock 28 splines although I have seen very few 8.5" rear ends actually break axle shafts,Smitty

I like your way of thinking. So the 12 bolt 30 spline axles are a proper fit into the 8.5 inch 30 spline posi unit? Would the axle length change due to the new posi unit or would they still be 30 1/8 long?

[smittyseng]

Originally Posted by 77TA406

I like your way of thinking. So the 12 bolt 30 spline axles are a proper fit into the 8.5 inch 30 spline posi unit? Would the axle length change due to the new posi unit or would they still be 30 1/8 long?

They might have been a 1/16 inch longer,12 bolt nova/firebird replacement axles,I bought mine from randys ring and pinion. They fit pretty good in the 10 bolt 30 spline eaton posi,I have had to trim the button the c--clip goes on before just ever so slightly,the nub seemed a little thicker than a ten bolt axle and couldn't get the clips in but it was just a few minutes to grind them slightly. They use the same wheel bearing shaft diameter too, Smitty