Quote:

Quote:

There was time(1960s-early '70's) when a lot of dragsters used 8 3/4's and cases were made out of different materials.. I would guess they were all 742 cases because the pinion isn't tapered, which is the weak link of a 489.




The weak link isn't the taper so much as it is the crush sleeve that can get loose with repeated hard usage. A solid shim replacement setup will cure that.



I'll stick by my comment unless someone can prove me wrong..
The spacer is one of two weak links on a 489,not counting ring gear diameter or deflection. 742's have(or used to) a much larger gear choice because of their strength(pin.stem diameter). Chrysler's "Performance Parts" pro gears were for a 742 case for a reason.

your turn..