This depends...What do you want out of your engine?
Top end (top speed, takes longer to get there)
or
Low end (quick acceleration but isnt as fast in the long run)
For Top end use a Jp-2
http://cgi.ebay.com/JAMMIN-OFNA-1004...QQcmdZViewItem
For Low end use a Jp-1
http://cgi.ebay.com/Ofna-Jammin-JP-1...QQcmdZViewItem