The C10's 10 bolt gets gutted and fully rebuilt with a new posi carrier, a set a 3.73 gears and new seals and bearings.
Check out the posi kit from JEGS
https://www.jegs.com/i/JEGS+Performance+Products/555/62806K/10002/-1?gclid=Cj0KCQiA54KfBhCKARIsAJzSrdpgg8Ir-gQfCcT1kathGCEIQKfNcHFnvImnUpiLb34f2Edf4JF2a-AaAi9fEALw_wcB
Check out my other Socials
lsmitch.com