A couple of weeks ago, I was servicing a GV in a 70's F250 w/C6, 460, 2wd, and it had what to me looks like an older GV (compared to Mel's here
). It had a rectangular sump plate, and when I removed it, it had a small filter above it, similar to a miniature AT filter.
She had just bought the truck a couple of months earlier, didn't know anything about the GV other than the added switch which she would leave in "autoshift" or whatever it was called, but she did have the GV manual in the glovebox. Wish I'd photocopied it. We were trying to determine what type of lubricant it requires (turns out to be Dexron II), but as a side note it also recommended an OCI of 12k miles.
The oil that came out of that GV was pretty much black. It didn't smell bad so I assume it was suspended clutch material. I sprayed a half-can of brake cleaner all over inside and then ran some clean oil through the fill hole with the sump still off, before buttoning it all back up and refilling.
So, there are at least two different versions of the GV for C6. Anybody have any other GV knowledge to contribute?