1993 Ultra - in-dash stereo wiring

[jeremyseattle]

My 93 Ultra - based on a Ford E-350 - didn't come with a stereo in the dash. I ordered a new stereo as well as a Scoche wiring harness, but the harness doesn't match up with the wiring in the dash. I have 2 female 4-pin bullet connectors, one male 4-pin connector, and some weird gray adapter that Y's off the climate control harness. Does anybody have any experience with this? I don't know if GS had a custom harness, or if this is the Ford cutaway wiring or what...