Description AV&V™ Solid Carbide Valve Guide Reamers Specially designed by AV&V™ for use with manganese bronze material, these unique self centering reamers feature a unique design with a long pilot for a perfect alignment with the valve guide while reaming.Do not use with cast iron guides You will ream a valve guide to exact dimension without any taper in 4 to 5 seconds only. Guides will last longer than with the honing method because there is no crosshatch left after reaming. One size allows you to fit both intake & exhaust if you use AV&V valves & guides.HIGHLY RECOMEND THIS WORK BE CARRIED OUT BY PROFESSIONALS.