i used my eyeball to line up the sprockets. i kept the frame a roller so that i could have the rear on there to match up the front. once you get the motor half ass mounted or positioned you can start to get it lined up. its really easy to tell when the chain is not straight. just move and position until its straight. not too hard but you wanna take your time when doing it. i bought a pro circuit pipe and cut, turned and added a little piece back in it. it was very simple to do. silencer was no big deal. i took a pro circuit silencer, whacked 5 inches off of it and added that back to the stinger and bam i was done.
no major problems with the engine at all. it vibrates some but not unbearable, in fact i dont even notice when im riding it. i dont regret it at all.