84 regal rear ends

[One quick6]

can anyone tell me if all regals in 1984 had posi rear ends.

 

[1986 Buick GX1]

I would say no, not all regals had posi.
When I ordered my GN in '86 posi was an option. It was standard in '87, but my guess is only on the GN's. I say this as there are a lot of guys that have '87 T-types and Turbo T's that run one air bag to compensate for the lack of posi.
The posi cars had a tag on the diff cover that said to use posi fluid, but the tags may be long gone due to slackers not putting it back on after service.

 

[pacecarta]

it was an extra cost option on all regals for all years except for the extended run of 87GNs built after sept 1987 when it became standard