I'm also interested in dropping a v8 in my stang. I've been talking to a guy named Victor Tyson. MVPerformance dropped a cobra engine in his 99 v6. Check out this site
http://www.mustangworld.com/ourpics/News/select2988.htm
He sent me some information about the cost in an email, check it out
The swap costed me around 11500. But that does not
include the rear-end, the guages,
suspension, bigger
brakes, or x-pipe. Here are some of the parts that are
needed and the prices as they were given to me.
cobra motor, transmission, brake master cylinder,
alternator, power steering pump, power steering
reservoir, AC compressor, belt, starter, clutch setup,
motor mounts, most hoses, starter wiring, injection
wiring, transmission wiring, flywheel, transmission
mount, transmission cross member, brain box, mass air
meter with air filter box and fuel pump sending unit,
speedometer cluster--$6600
radiator, fan, shifter, power brake booster, shifter
boot, clutch pedal assembly, and labor to install
everything--$4800-maybe a little less.