actually it would be easy to put a C intake manifold on there with minor trimming. I was thinking of doing an aviator intake manifold with CyKlone intake top hat.
there has been some write ups. just takes some trimming. bolt holes line up and ports are damn close to same size. now the navi heads are a lot bigger than both.
headers wise all people do is oval the mounting holes just a little. I put up 4v exhaust gaskets and they looked great.
These are bolt on ready. These heads have springs that are designed for the high lift of the cobra r cams so they will be able to handle most aftermarket cams. They have modularheadshop.com viton seals. They have had all valve seats lap'd(absolutely no pitting or problems). The ports were cleaned up by myself and then had them flow'd. They have been surfaced as well. I will be sending brand new Ford GT intake gaskets($70 a piece) with them.
if you want to talk about them pm me and i will give you my cell phone number. my email is watsonb61@ y a h o o. com