i'd go for the cobra...
I did, actually
the nice thing about the cobra is the forged crankshaft, which is stock. since the block is all aluminum, i'm not sure if the 6-bolt mains are an advantage or not...
a nicely balanced 4.6 is good to 7500 RPM

throw in some billet rods and a girdle, and you're looking at over 8500 rpm! (
http://www.seanhylandmotorsport.com)
i love my 5.0, but it is set up to drag, so it is a bear on the street. the cobra is equally at home on the street/strip/twisties or wherever...
good luck!
