KPMI, intake valve guide. Manganese. STD

MCS-588711 - Maganese bronze. Standard size: 0.4750" O.D. (12.07mm); .2347" I.D. (5.96mm); 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 do

Fitment:
17-21 M8