Slight speedo cable leak...and other questions

Thanks fishy68 and TrailBeast for the ins and outs of a 904, tranny fluid compatibility, how my morning startup will now be and staying with the 46RE pan gasket....is a 46RE pan gasket all I need to say to the Mopar parts guy? Are they usually in stock or a special order? Also, is the fact that it's a lockup 904 going to change the number of qts. of tranny fluid needed for a change (not draining the TC)? So with the tranny being a 83 with a lockup TC, will Dexron III be okay or should I move up to a higher designation? Looking forward to your responses so we can put this one to bed...
All the Best,
Greg

Dex 3 is fine, and is as good as any of them, and you should have probably at least 6 quarts on hand to do the fluid change. (8 if you let it drain for awhile)
The 46RE gasket should be in stock (I would think, since the dealer regularly does trans services)