i want to get posi and 3.23 or 3.42 gears for my rs. it seem to be about 4 times cheaper to buy a 4th gen rear than buy a posi diff and different gears. my wheels have 6 lug nuts holding each wheel on. 4th gens rears have 5. i know ill need front spacers. i need some explaining of how this'll work

 

GM never built a third gen with a 6 lug rear- if you have one in there its not stock and probably stronger even than the fourth gen rear. That point aside, yes it would be cheaper in the end to buy a fourth gen rear end, especially if you intended to upgrade to disc rear. As far as the rims, 3rd gens use different back spacing than the fourth gens did. From all the sources I could find, 2" spacers are required to run fourth gen rims on a 3rd gen because the axle was narrower. No spacers would be required for using the rear and rims from a 4th, but you would still need front spacers. Hope this helps,

 

i don't no what i was thinkin i just checked and it is a 5 lug. installation should be straight forward using the tech article?