[Sailfish]

As a new Superformance Cobra owner I struggled with the same question. I wanted a big block, but the extra weight was a hindrance. I finally settled on a small block----Roush 342R. It's light weight, makes good horsepower (450) and obtains high rpms quickly. And, it's fairly docile around town. Plus, it's got a 2 year warranty. Granted, it's not faithful to the original, but all things considered, it provided me with the best bang for the buck. Regardless which engine you choose, it's still a Cobra and you'll have a lot of fun!