They are all over the net. I haven't got the latest for motorsport catalog, but I am pretty sure they have them listed in there too. The thing is, they are probably sourced from on of the people in the following URL.
There is a company ...painless wiring... that has been in the business for a while. I hear they have a good harness kit, I see it mentioned in a lot of hot rod magazines and meesages on boards.
Did you check the Tech department?
I can't do your homework for you...well I could, but I'm lazy... Anyway, here are some links to get you started. Nothing wrong with getting one off a junk car either...except
1.) why was in the junk yard in the first place
2.) chasing down problems on a harness you aren't too sure about in the first place, can cause baldness.
3.) some of the kits from these guys hae instructions on what needs to be hooked up and how to do it. Unless you have hidden talents with electronics, it can get pretty intense chasing circuits.
that's enough...for now.
http://www.corral.net
http://www.windsor-fox.com *
http://www.50tech.com
http://www.caford.com
http://store.wpsracing.com/painwirfueli.html (Fuel Injection Wiring Harnesses, Ford: 1986-93 5.0L/5.8L, Mass Air Flow engines PAI60510)