Be careful when you say "modular." A lightly modded N/A 4V would hand your car it's ass.
The 97 is a viable contenter once you consider a few things....
A headswap for a 5.0 is going to be just a few hundred bucks less than a 2V head swap. Once you cam and gear the 2V right, it'll run right with any heads/cam/intake-swapped 5.0. The aftermarket is starting to come around for the 2V cars - once there becomes a larger selection of camshafts, manifolds, etc., the 4.6 2V will really start to show that the difference in cubes (between it and the 5.0) doesn't mean much.
Joe