Re-power with crate LS3 (LS9 CNC-ported heads, 220-230 117+4 cam), rebuilt by GM 4L70e, TCI 2,900 stall bolt-together torque converter (https://www.tciauto.com/bolt-togethe...-2900-rpm.html), Amsoil fluid. I'm getting chattering during lockup, and lockup is not holding. Any thoughts?