yep there is. The red 202s are 9 port head, blue and black 202s 12 port. The ports have minor difference for the manifold but the main part is the studs for the exhaust/manifold. These studs are in different spots.
depends, there seems to be alot of mixing with and blue and red manifolds, eg efi manifolds on red heads, strata manifolds modified to suit the other and extractors swapped, I think some manifolds are even universal like redline hi-flow2 (is that what its called?)
If you are going to a 350 I would stick with the varijet, SM magazine did a story on the blue motor were they would change something and test it, then do another change and test it again, what they found was the varijet carb made more power than a holley 350 on a blue motor, might be a different story with a better suited carb like a 390 4bbl.
My 12 port has very large ports, when I hold a strata red manifold to it the port is bigger than the outside of the manifold so thats a no go.
If your head is standard you mite pull it off with a little die grinding to the manifold but I dont have a standard head to check on, if you need manifold measurements I have a speco and a cain holley 2bbl manifold as well as a standard red, standard blue, strata turbo and efi manifold here, I have 12 and 9 port heads but no stockers.