This is our basic differential cover, we see it as the only one worth making. It is a 1 piece Plate steel cover bent 8 ways, way hard to hurt in .375 (3/8"). On the D60 / D70 the ring is also .375. The fill plug is a generous 1" ID for easy fill and oil level check. One of the reasons it is so hard to hurt is that we manufacture it out of A50 Plate Steel, thats 50,000 PSI Tensile strength. The D60 Differential cover is our best selling cover and for a good reason. After welding the mounting surface is machined absolutely flat for a perfect fit! This is for a fully welded D60 / D70 High or Low pinon Diff Cover, welded inside and out. D60's & D70's use the same cover.