ok guys, some of you know im looking for a engine for my skybolt. i have a 70 surpass, but some have told me that really wasnt enough. how about these engines? GMS 1.20/Magnum 180 AR/ST2000(25cc)/ST 3000(30cc) Or Super Tiger G-90 with Standard and Pitts Style muffler. Which one would you go for and is any of these engines a good trade for a 70 surpass brand new? TIA