Currently deep into the "might as well" stages of my GT350 track build and the subframe is sitting on the shop floor, wondering if anyone has installed poly diff bushings or lockout kits on their 350. Ideally I don't want to increase NVH drastically since I still drive the car to local tracks. Everything I've seen has pointed to it only being necessary for drag applications but wanted to get any input I can before deciding to or not to modify.