I am seriously considering converting to mass air in my mark. What exactly is needed from START to FINISH to convert the mark VII from speed density to mass air?

See these:
http://lsc.netherealm.net/maf.html

www.mass-air.com

Is the mustang computer in located the same spot as the mark VII is?

Yes. . .

Thanks Sif, where you been???

Just been busy.

Since you have an '87, you can keep your cruise control when you swap.

Since you have an '87, you can keep your cruise control when you swap.
COOL :Beer

How about an '88?

How about an '88?

'88+ cars no longer had stand alone cruise control. You will need to add in a Mustang's cruise control system (not too hard) or run your engine computer in parallel with the mass air computer from a Mustang. The former is obviously the cleaner set up, but both have been done and both work.

Unless you plan on really adding things that will greatly affect the fuel/air ratio needs of the car, I'd leave the speed density. Changing to MAF won't help much if anything until you are at the point where SD can no longer compensate for the things you have added. The MAF sensor is actually a small restriction in the air tube. I know one guy who has a Kenne Belle supercharger making 300 hp or more and still runs speed density just fine. His name is Bluegrass on LincolnsOnline.com. He's very knowledgeable and would be glad to help if you keep the stock system.

Alright thanks. That would be my last hurdle. My plans are AFR165 heads, some sort of intake manifold (leaning towards FFRP or BBK), long headers/exhaust, e cam, cold air intake and after all that is sorted and running fine. I want to slap on a Vortech.
If I'm not mistaken, that will bring my in any case close to 500. So I would probably have to swap out to MAF just before installing the blower. No problem though because I have already sourced some second hand Mustang parts. Besides, cruise control isn't really needed on a 40 mile long island anyways.