I want to switch my 10 bolt stock rear gear to a slip posi. and was wondering how many teeth are on the rear axles so I get the correct Differential (30 or 33)? The one that's in the truck is a 2.73. and with my motor I get no traction so I'm hoping the posi will help.
Should I go for the Posi 2.73? I only get 8 mpg as it is.
1985 Silverado
383 Stroker 425HP+
TH 350 B&M shift
12" wide rear tires