12 Bolt differential

[srmedic]

I have a 12 bolt open differential on my 68 CST c10 pick up truck, 383 stoker ,600CFM Edelbrock carb,TH400 tranny with an open differential. I have tried to figure out what the pinion ratio is by jacking up the tire spinning the wheel twice and counting the drive shaft rotations. The drive shaft rotates just over 3 times. My question is if I buy a new Eaton carrier and 3.73 ring and pinion will it fit into the axle housing I have now? I have a pinion seal leak and I also want to add positraction differential so I'm not spinning one wheel for ever and I can finally get some good traction. I run about 2000RPMs at 60 mpr in 3rd gear.