[fastd]

Target hp/torque, target rev limit, target compression, tires/rim size are important factors in informing the answer to this question. Gobs of torque from a big block is great fun (for some) but doesn't make the car a good driver, especially for the kind of driving you expect to do.

Lighter weight, higher revving engines just feel better in a Cobra imo. The higher the compression, the more difficulty a carb will have with today's 93 pump gas. Best bang for the buck is a fuel injected 351w with aluminum heads, assuming you'll have compression above 10+, imo. I added about 50-75 hp to my engine; the car now dynos at 425 hp and 402 torque at the wheels and honestly I would not any more power in it. And if I had to do it over again, I probably didn't need the extra 50-75 (but I like the aluminum heads that I added). Maybe I'd feel differently if I didn't have 15" rims, i.e. with 18" michelin pilot sports, would feel better about holding that extra power.

Also, try to find one with a return fuel line or add one yourself; nice if the pump is in the tank. Test drive it on a hot day.