Riot Standard Barrels bushings are the go-to bushing. They are 0.605" tall and fit perfectly in many RKP (reverse kingpin) trucks like Caliber, Paris, Bear, Randall, etc.
Riot says: "They start as rods of our perfectly cured, high-quality blend of urethane we call RiotThane. They are then turned on a lathe and profiled to very a precise outer diameter. We then machine the hole in the bushing, keeping our tight tolerances, to ensure that the bushing fits SNUG on the kingpin and is perfectly concentric with the outer diameter. Lastly, we part the bushings off to tolerances often not seen in molded bushings. This ensures very precise alignment of the hanger on the baseplate. With the bushings being machined, we can guarantee a near perfect product every time."