I have never heard of the two different keys. Every time I order a timing set I just specify the year. Here is how Summit lists one set:

Make FORD
Engine Type V8
CID 302
Liter 5.0
Engine Size 5.0L/302
Beginning Year 1968
Ending Year 1995
Engine Family Ford small block Windsor
Block Align Bored No

And the general consensus is that you really don't want a gear drive. They cause more problems than they solve. (premature wear, noise gets on your nerves, etc.)

Don