We manufacture these large billet aluminum fill cap & bung assemblies in house using only domestic material and we make them in a couple of different finishes with either a steel or aluminum weld in bung. The weld in bungs have a 2-1/8" opening, an overall bung diameter of 2-3/4" and feature a step on the backside to make ease of locating while welding. The billet aluminum fill cap has and overall diameter of 3-1/4".
