okay I KNOW what they do, whats best etc... don't tell me. what i wan't to know is, are 1.8 or 1.9 rockers more reliable. and are roller rockers worth it? I also have ls6 valve springs and retainers. i know i need to run those with the 1.9's. if i went with the 1.8's i know i don't need the ls6 valve springs, but is it better for the car if i used them with the 1.8's? im looking for the safest/least harmful to my engine setup. I drive 35k miles a year and whatever i do needs to be the best. a cam is out of the question. any input helps thanks..