Hi Robo,
I went down the same path as you when I first started looking at a Cobra kit. I have a BB Chev and 4 speed sitting under the bench and figured I'd stuff it into a Cobra.
A little more investigation revealed it would be very hard work to get the Big Block through emissions so I decided to go modern and high tech and there is a Gen3 and 6 speed sitting between the rails now.
The big block is still under the bench and it can go in an A model roadster for the wife
Anyway welcome to the club. You will find a huge pool of knowledge here and probably an answer for just about any Cobra question you could think of.
Cheers