neither reall, i would get a T3 super 60 or a T3/T4 but out of the 2 your have the straight T3.....

your LS motor doesnt need to wind up to 8000+ rpms, and neither of those turbos will make power way up there either, you need power a little lower where the LS makes all its torque. use a T3, it has super fast spool and great power.

also you might wanna choose a different tranny too