68 Nova ???

[bbdon]

Dave, I am wondering which code it is that you are talking about. The build sheets that I have seen do not mention if the rear axle is 10 or 12 bolts. If positraction was ordered the build sheet might mention that as G80, but that would be available on cars with 10 bolt rear end as well as the 12 bolt models. I think that Chevrolet selected the rear end type for you based on the engine and transmission combination ordered, and did not let you choose.