I have the Haynes Manual but it doesn't help my particular application (seems to me that I have a modified 87+ harness w/ 83 dash connectors. I decided on just find another harness out of some other
stang and put it in my car (I'll never be able to make any sense of this one considering I didn't modify it in the first place). It will probably save me plenty of headaches in the long run.
BTW why did you go from a 91 to 93 interior? 87-93 are identical (maybe I'm wrong). It should have bolted right in. I know in my application I had to install a new heater box as well as cut off mounting brackets in my 83 to fit the new dash.