Intake Valve Guide. Fits Sportster 1957-Early 1983. Standard Outside Diameter Guide

Cast Iron: After chemically separating several samples of cast iron material , analysis and evaluating the test data, we decided to have our own specification of cast iron made exclusively , us. We specify elements such as carbon, silicon, manganese, nickel, chromium, copper and sulfur to produce a highly pearlitic structure with dense fine grains , excellent wear resistance.

* OD = 0.5650" Std size

* ID = 0.3085"

* Replaces OEM # 18176-57

Matching Exhaust Guide # KPM-20-2330C