KPMI, exhaust valve guide. Manganese. Std

Manganese bronze. Standard size: 0.4750" O.D. (12.07mm); .2342" I.D. (5.95mm); 1.655" OAL (42.04mm). Manganese bronze is softer and less durable then C630 bearing bronze but will allow a lower cost and reaming to size is quick and easy and finish can be done with simple tools like a ball hone and an electric drill. Rapid heat transfer and good lubricity.