supercharge on carb

If you are going to keep the serpentine belts, you can just do what I did. Get a supercharger kit for the 5.0 and get a carb hat. You'll need a single plane intake and a modified mechanical secondary carb.
 
Turbomustangs.com
Ideas on super and turbos. Both are mostly the smae for areas that you will concerned about. Beware though. Don't go on and ask a Q like this. All they will do is tell you to do is search. Their data base for blo thru is incredible. You will find all you need there.
 
Just my .02 -- don't let the complexity of EFI scare you too much. It's not as bad as a lot of people make it out to be, and the extra effort pays off lots of dividends in driveability, power, etc. Not everyone would agree, but I recently (this year) got my 5.0EFI installation working in my '65 and am jumping up-and-down pleased with the results. :D
 
just finished adding a ATI procharger to my 65 with a carb. its totally insane. i took a used 5.0L mustang kit for a third of what it costs new and i modified most of the brackets and accessories to make it work. turbomustangs is the place to go. just about everything on blowthru carb setups is on that site. the most important thing is to make sure the fuel system is adequate. you actually need a EFI pump if using an electric pump. a modified mechanical pump will work just fine for about 450hp. maybe a little more. the paxton novi1200 kit is nice and includes everything you need. i would ditch the carb box and go with the EV bonnet. if anyone claims gas will squirt out of the carb if you use a bonnet they are wrong. my car makes 9lbs of boost with no fuel leaking from anywhere. and all i did was follow the instructions on turbomustangs for modifying a holley carb. the carb route is definately worth the effort and expense i hope you decide to do it. it has some good advantages over EFI when adding boost.