Well, I have access (my son's care was just totaled) to a 4.6L 32v dohc Ford motor. Then I look in my shop at a 1976 280z that I am working on for my daughter, and I am thinking this could be interesting. However, I am only moderately mechanically inclined, can weld fairly well, but do not have a machine shop. So, am I nuts for even considering such an adventure?

Hybridz.org is the place to learn all about engine swaps. If it's possible, someone there has probably done it. Make sure you search and read before posting questons, they aren't very tolerant of people asking things that have already been asked and answered in the past.

From the looks of it, it can be done, but will require a fair amount of fabrication.

460ZGT Project Build

I'm betting that 4.6 is too wide.

You can think about it but don't do it.

Looks like a lot of work mechanically, and to really get the full power potential you will need to cobble up the engine control unit from the Mustang. If you are only as you say "moderately mechanically inclined" I suggest that you get help with the things you don't understand.

On the other hand a 400HP engine in a 2400 - 2800 lb car would be interesting. Better upgrade the brakes (think Wildwood style 6 piston calipers in the front and 4 piston in the back), a roll bar, and your daughter may need to spend some time at a racing driving school, because this thing would be a monster.

very wide motor.

I had a cobra kit car with a 5.0, which has an engine width of 19 inches versus close to 30 inch for the 4.6