I'm a Mazda tech by trade, and have done hundreds of bushings on Navajo trucks. These are the bushings that slide on the the arm right after the "cupped" washer, and the arm actually pivots on the bushing at the frame mount, not the black bushing or white plastic ring after the frame mount. They have a basic shape of a "mushroom". I've never seen any like them before. At the actual pivot point, where contact with the frame and bushing takes place there is a band of metal about 5/8" wide, looks like stainless steel bonded to the bushing. It's the right side bushing that gives me problems, because its along the exhaust side, and yes the heat shield for the actual bushing is installed. I'm thinking these bushings must be an aftermarket or off road brand I'm unfamiliar with. There was nothing wrong with them when i took them out, I just thought I was doing myself a favor by replacing with new. I live in Fl, near the beach, and the sand chews the bushings up, and you'd be amazed how fast they can wear out here, depending on your driving habits and locales. If I ever find them, I'll post again, because these things are "bulletproof".