What years did GM offer posi?

[evil_admin]

My 83 s15 has a posi and im curious if it was a factory option or after market mod.

[speeder]

my 84 came with limited slip diff. with springs, like auburn lsd

[dynlub]

I had a 1660 Pontiac with posi. TOM

[dynlub]

I had a 1960 Pontiac with posi. TOM

[327Isuzu]

Posi has been available since the 50\'s. GM has offered it continuously on rwd models.

[evil_admin]

what about on the s-series?

[327Isuzu]

It was an option every year of manufacture. Never very common, but an option none the less.