can someone give me the pros and cons of running a lightened crankshaft pulley,mainly unorthodox. someone told me not to do it because i'm risking my motor. what?

 

make sure you get a good one. my friend got one for the same motor...and it fucked it up cause it didnt have the numbers to time it. so make sure yours does. he had i/h/e/powerpulleys/underdrive pully/ no ac or ps and he beat an EP3

maybe the guy coulnt drive i dont know..but true story