So this came up in discussion. A person I am not familiar with claimed his 84 Trans Am came with an Eaton Posi unit from an S10.
Reasoning: There was unexpected sell numbers for 84 Trans Ams and they ran out of parts, so they grabbed posi units form the S10.
Evidence: Claimed he had a discussion with a GM engineer who told him why he had that posi unit he had asked this question because his car had one in it when he rebuilt the rear end but was not the original owner.

I am not saying this didn't or couldn't happen. I am sure they didn't expect to sell 128,000 (IIRC) T/As in 84 and both used a 10bolt... and my understanding is the carriers are a direct changeover. However, I question this because we have all heard the "special" parts stories. I would just like something corroborating this story beyond anecdotal evidence.

I have been around thirdgens a long time and this was a new claim to me. Is there any validity here? Does anyone have any evidence to support this? Was the Eaton supplied OEM part for the S10 even an upgrade over the 10Bolt in the F-Body?

 

I doubt it "came with" a Gov-Lock. BUTT, in the early 80s there was a CHRONIC shortage of posi carriers, so it's not at all impossible that they did that at some point out of desperation. Or, that the stealership did it for them; which, to me, seems FAR more likely.

Can't imagine how a Gov-Lock could POSSIBLY be considered an "upgrade" over ANYTHING, in a vehicle designed to run on pavement. Just IMNSHO.

 

My 84 TA came with a Gov-Lock.