What rear end do you have in the truck? Some rear end styles have fewer limited slip carriers styles available.
If you get a 12 bolt 3.07 or 3.42 carrier to run the 3.73 ratio you would need to get a thick gear set. The thick gear set has some limitations. With a 6l80 transmission I wouldn't think twice about running 4.11's for a daily driver Burban. Much quicker when shooting around town.
I am running 3.73's on the 3.07 factory posi carrier (thick gear set) with 28" tires. With a T400 and limited highway driving it works well, but I don't run much above 60 mph for any length of time.
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Thanks to Bob and Jeanie and everyone else at Superior Performance for all their great help.
RIP Bob Parks.
1967 Burban (the WMB),1988 S10 Blazer (the Stink10 II),1969 GTO (the Goat), 1970 Javelin, 1952 F2 Ford OHC six 4X4, 29 Model A, 72 Firebird (the DBP Bird). 85 Alfa Romeo
If it breaks I didn't want it in the first place
The WMB repair thread
http://67-72chevytrucks.com/vboard/s...d.php?t=698377