Thanks to all who have given their input. I would like to hear from anyone else who has an opinion as I value many different view points. It was looking like this might turn into a big block vs. small block "discussion", I'm glad it didn't. To answer a couple of questions, I want my Cobra to be a very powerful all around car. Mostly for street use, but I do plan on taking it to some open track events, and occasional drag an autocross use. I am willing to trade off some handling for the power and sound of a big block. I agree that for pure drag racing a well set up automatic is best, but I want to shift the gears in my Cobra, so I'm using a Richmond 6 spd. Having the O.D. will be nice for cruising. As far as need or practicality, I don't think those words really apply to Cobras. Who really needs a Cobra with any amount of power? Practical?......Please!
Cobras are all about wants. Having said that, the point about professional drivers having difficulty handling the original cars is well taken. Just about any Cobra needs to be driven judiciously if one wants to stay above ground a while longer. I am of the opinion that just because you have mountains of torque and hp, doesn't mean you have to use it all the time. On the other hand, having more power that you can really put to the pavement, doesn't not help you. I would consider getting a set of drag radials or slicks for drag racing, if I got into that more seriously. Of course that increases the chances of breaking a diff, U-joint, or axle. Can a Jag rear end and half shafts handle all of the power that can be put to the ground with street tires before they slip? This is without dumping the clutch at 6000 rpm in 1st.
Another issue is safety and track rules. I am not well versed in drag racing safety rules. Mostly written by the NHRA I believe? I know most drag races and tracks require certain safety equipment (i.e. roll cages,etc) if you run under a certain time. Although what I have seen of events like Run & Gun there seems to be Cobras that run in the 10's with little more than a helmet, standard roll bar, and racing harness. These articles never talk about required safety equipment, but that doesn't mean there isn't any. Is there places and events that a Cobra can run in the 11's or 10's in just the standard S/C trim (i.e. roll bar and harnesses)? Obviously the driver is accepting greater risk by doing so.