Change carrier in 12 bolt to posi

[hooperca]

Hi all. I recently purchased a 67 C10 with the factory 3.73 12 bolt in it. I removed the back cover and everything appears to be in really good shape. I would like to put an Eaton posi unit in it. Can I change out the carrier using the existing gears? I've been told I wouldn't have to bother the pinion at all. Just make sure the backlash stays the same as it is currently. Thoughts on this? I really don't want to take a chance screwing up the gears but a posi sure would be nice! Thanks!!