I haven't done anything to mine. I've been as quick as low 11s, but I have also put 1000s of rounds on the car in the last 15 years with the Calverts so a lot of potential wear and tear. Car is up on the lift now getting a new fuel system, leaves, mounts and Cals look just fine. Shock bodies are beat up from burnouts and such. 4.56 9" with a 4600 stall converter, so I hit the tail end hard every pass. Having said that, it'd be easy enough to craft a 1/8" steel reinforcing plate to stiffen either the outside or inside with a shaved bushing. Remember in a leaf spring, the front half is just a locator and the back half does all the work.