danger, when i first started modding mine, i removed the paper from the oem filter, yanked the governor and ran a straight pipe. my engine doesn't run as fast as the builders claim it should. propper jetting is a must for any engine. i ran 50wt oil in the beginning, 5-20w30 is fine. remove every other fin from the plastic fan. i doubt anyone has gone through tests with a stocker running along side modifieds to see if longevity is the same as with the stock configuration. if you build it up correctly, it will last. as to how long, mainly depends on maintenance and how it is used.