My GTA has option code gw6 = 3.27 rear axle

What is the difference between this and the G92 Option.

 

G92 was 3.42 gears.

 

In the first years of the Third Gen it was a only a gear option
but after 1984 or 85 it became a performance option that's
include the Australian 7.75 inch Borg Warner rear end with
Performance ring gear ratio 3.45 for the 305 and 3.27 for
the 350, disk brake, engine oil cooler and a better cam for the
305 LB9 (TPI) 5 speed.

The WS6 option for Pontiac refer as perfomance suspension option at first but like the G92 option there has been more
update with the following years...
All in all i think it"s the same option but with some minor
difference in the supension departement.

 

G92 refers to an optional rear gear, not a specific ratio.

If a GTA could have had 2.77 or 3.27, then 3.27 was the G92 gear *but* 3.27 has its own RPO also as you've found: GW6.

In the 70's, if a drivetrain came with 2.29 standard, and 2.73 optional, then the car would have G92 RPO with the 2.73 rear.