THe heads on the Cobra were not as restricted as the GT heads, but they werent much better either. THey are production style GT40 heads, more or less.
THe intake should do you to 400HP or so,but you can port it for more.
the cam can be changed, as it isnt much better than the stock GT cam. Put some headers on it, run your Cobra intake with the TFS heads and a TFS stage one cam, and you should put down some good numbers.
You will wanna change your rockers to stud mount too, as the TFS heads wont accept the stock style CObras. but, you can sell your CObras to someone racing in NASA CMC, as they are all running stock heads there.
You should also be able to sell your stock heads too, then you can re-coup a few hundred.
Remember to have it dyno tuned, as the 94-95 computers are finickey, and dont like major changes to the engine like this. you can also swap the pins in the harness, and go with the 87-93 style processor, but you gotta set up your electric fans.
Hope this helps!!!