i went for unorthodox because of the crank. it comes with power steering, alternator, and crank pulley. if you have a system keep the stock alternator pulley on. top speed? where can you go 100+ mph?? who cares about top speed worry about acceleration. check this site out it will answer all your questions and it gives great info.
http://www.unorthodoxracing.com/faq_pulleys.html