I feel like I let you down with just partial advice. Most 265 left side manifolds are drilled and tapped at the front for the factory generator bracket. A short piece of 3x3x1/4 angle iron with holes drilled to align with the factory bolt holes in the manifold and the other flange on the angle iron turned back over the top of the manifold will give a surface to fasten (weld/bolt) an alt/gen bracket to that will hold the alt/gen away from the inner fender. After fitted the angle iron can be trimmed and corners rounded to look pretty.
