A car show acquaintance recently perched a 68 Dart with a V engine, and 8 3/4" rear 3.91 gear in 421 case, with limited slip, He did not know if it was an Auburn or not.

He replaced the above housing and gears for an open 489 case with 3.24 gear. Now he wants to add a limited slip unit to it.

Can his old limited slip unit be installed into the taller geared member with different case?

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

I have no idea what a 421 case is. 741, 742 and 489, sure. The Sure Grip units between those interchange, but the carrier bearings match the case not the Sure Grip. So you may have to pull the carrier bearings.

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Joshua

Some more info here:

http://www.mymopar.com/Mopar8_75RearEndGuide.htm

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

Josh: Just an utterance conjured up from an addled old brain exposed to too much sun yesterday; it’s my life’s story to indiscriminately jumble up numbers on occasion. Sorry for the confusion.

Out of excuse zone:

It was 741 or 742, this morning I don’t recall which as he was rattling off various combinations of the above numerals. I’m positive original pumpkin was not a 489 that he wants to stuff a limited slip unit into.

Rick,
Your hot link answers his question. Both types of limited slip units interchange between all three castings as long as matching differential axel bearings are used. The outside dia. of the cups same between the three castings; the inner cone differs. Differentials manufactured before 1964 have interchange problems.

Thanks guys, I’ll pass this info along, and hopefully this will even out his rear tire tread depth in the future.

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC