OK, let's get to it. Are you ever going to attend a cruise-in and pop the hood, seeking some "ooh" and occasional "ah"? No? Stick to single quad. Yes? While the 3-2V takes initial adjustment, once you're dialed that's it. I ran one daily in a 410-powered '67 Cyclone from 1976 to 1978. Once dialed, I never had to babysit.
Now, that was in the 70's. Presently, the carbs are older and attention must be given to the possibility of warped components. It ain't gonna be plug 'n' play. Also, the ports in that intake will extend below the ports in the C7AE heads, so you have to be careful about proper fit and gasket choice to keep from sucking up oil vapors. I did this on my C7 heads and had no problem. The equation will include the extent, if any, that the block and heads have been milled.
Your heads have 8-bolt exhaust bolt pattern. Stock Galaxie manifolds may physically fit the Mustang, but you will have to loosen the engine mounts and jack up each side to change plugs. Option A is to contact Stan at fordpowertrain dot com to get the right pipes for that head/chassis. Option B is to switch to a 14-hole head and run factory GT manifolds. Option C is to have your existing heads drilled for the GT pattern. Option D is that Sanderson may have shorty headers that will work.
