Yes, I just bought one the other day but haven't installed it yet. The disadvantage would be the lack of horsepower that you would gain with the original heads if you went to the 4v. MM did an article about adding the intake back in Dec. or Jan. but I believe it was an original 4v car. Does your car have a dual exhaust system? If not I would do that first.
66 Signal Flare Red Vert
302 2V, 15X7 Cragar SS's with 205/60s
I may be mistaken, but there aren't different 2V and 4V heads for the 302. The heads are all the same with the exception of different sized combustion chambers year to year. I agree with doing the dual exhaust. I've got duals, full tube headers, a Performer 289 manifold and a Holley 4V on mine and it makes a big difference. The gears didn't hurt either.
As I understnad it the heads are the same. They are different between 2v and 4v on the Cleveland engines but not the Windsors. You will notice a little gain with the Performer manifold and a 4v carb (I recommend Edelbrocks). But uncorking the exhaust together with new induction will yield noticable changes. You can then spend another $25.00 to recurve the distributor to get the ignition right and you will have a quicker car. Next, rear gears. But the answer to your question from my perspective to to go for it. But before you do, try to envision how you want the car to be when you are through so you don't have to do the same job twice. What comes to mind is someone spending money on a dual exhaust only to relaize that they wanted a larger pipe size.