[STL Mark]

I trying to decide what engine to put in my new SPF (when I order it). I am planning to have Eric at Performance Engineering do the build/install. I'm trying to decide between his 427 Windsor and his 557 big block. The 427 has an option between iron block or aluminum block. So my question is what are the preformance, reliability, and maintenance issuses with that choice. Why would I choose one over the other (considering the price difference between the 2)?

Also regarding the big block - I've been told that it's not "very streetable". I'm new here - but what exactly does that mean - bad gas milage? breaking the tires loose at anytime? both? more? I notice that a lot of people here have 600+hp cars, so is it just a "learning curve" on how to handle a car with that sort of power to weight ratio (without wrapping around a tree)? What do they men when they say - not very streetable. Again - new here - very excited to be able to finally get a cobra - go easy.

Thanks for any help
Mark