i have an 84 Z28, and i need to upgrade to a posi, ive heard of 75-76 caddy seville posi units just bolt into a 69 bird, read that in High Performance Pontiac, i was wonderin wut were some options besides a 4th gen rear, i would like to have 3.23-3.73 gears, must be posi, thanx for any help

 

nothing bolts in to a thirdgen accept for a 4thgen rear, or one from another thirdgen f body. thats why the rears suck (besides their the weekest ever made by GM). you can also get a modified 12 bolt or 9 in. (aftermarket) but plan on spending like $3000. best bet is to get the slp stock posi unit ($99) and 28 spline axl's ($125 ea. aftermarket or bone yard 89-newer f-body)

 

where do you find $99 posi I want one?web site what to look for I know about 28 spline axles