Things you did/upgraded that surprised you how helpful they were

Went from 9/10" convertors to 8" and picked up like 3 tenths in the 1/4.

Went from tube/fin to plate style transmission cooler. Trans gauge is in bottom of pan and would see 220+ with tube/fin style. With plate style never been over 190.

Went from Comp Engineering 90/10 shocks to QA1 stocker. The adjustabilty on how to make the car leave/react was surprising and another helpful tuning tool.