Sorry. To me "gear oil" is the age old "used to be" 90 weight, nowadays also multi-weight such as 80-140 or whatever.
If you read the service manuals, under certain conditions Ma recommended ATF which for traditional Mopars "used to be" same as PS, IE Dexron ATF
The thing is, "I don't know" what you'd get mixing the two. They are very different products. This is not like, say, putting 40wt oil into an engine with 10-30 in there.