not real difficult to achieve, however if you haven't bought the big block yet, might want to reconsider. The 5.0's and modular engines with the right goodies will make a bunch of power and still retain all the good street manners necessary for heavy traffic areas... Just went through an email session with Kenne Bell Superchargers regarding the new Coyote 5.0...easy to get 550 at the wheels with one of them but even the 4.6 two cam engine can easily put 500-550 to the wheels leaving the rest of the engine stock!!!!! Might want to check their website.

I've done a number of BBF in a Horse builds, they work well IF you address the weight issues and go with a cam the manufacturer sez will work, and not just the biggest, ugliest, lumpiest cam in the catalog!!! IMO a quality set of aluminum heads, aluminum water pump, aluminum intake, relocated battery to the trunk, 'glass pin on hood will help with the weight. It also takes frame ties, torque box reinforcement, some Cal Trac (or smilar) bars and adjustable (lowers at least) control arms to get the torque to the wheels and not just absorbed in the Flexi Flyer body. Convertibles also benefit greatly from a 6 or 8 point roll bar (S&W along with a host of other companies sell a bolt in version) to make the car "work" right with all the added torque. Lots more to it then just bolting in the big block!!!!!