OH NO! A 4L60E vs 4L80E thread.
A well built 4L60E with a few upgrades will work fine on a mild LQ9.
The 60E & 80E are built pretty sloppy when new, & the valve body calibration sucks. The 80E is a stouter transmission & can handle abuse longer. But comes at a price.....Being Bigger, Heavier & Robs more power.