the "LS-7" lifters as are used on a large amount of GM cars, so they would be an OEM replacement, not a performance lifter as mentioned. Stay away from the comp cam ones if possible. If you want a proper XP cam setup, go with the double roller and 125/130lb springs(this will allow you to rev the motor safely to use powerband offered from the XP). While you can use the 90# springs, you risk valve float and reduced power. You have to keep in mind the more power you make the stronger springs you need. Most people that suggest the LS6/90lb springs dont know what valve float feels like, and lose power reving higher. This has been dyno proven time and time again. Rising boost numbers past 5800 RPMs is a common sign of a weak spring.
good luck of the build
FYI sound is never a good reason to choose one cam over the other. Your trans gearing and the rest of the setup should be the deciding factor.
