No matter what you intend to do with your 4L60E, toss the existing clutch steels and go with new, high-performance frictions like the ones from Raybestos. See All 26 Photos 6.

This 4L60E goes from parts to performance. ... hardened drum and sun shell, and, of course, Raybestos clutch packs. ... The Stage 3 drum is a hardened unit with a bolt-on pressure plate (shown) ...

A big issue is excessive backing plate flex when the clutches are applied. If you can see spending another $500, Sonnax offers the Ultimate 3-4 Smart-Tech housing combined with a stronger input shaft.