Just bought an NOS mirror for my '74 'Cuda, it looks identical except the mounting holes are further apart than they're supposed to be. The part I got is 3670981. Does anyone know what this part is for, or what the correct part for my '74 car is? I was told by the seller that this was the correct part, my fault for not checking it out. It came with a rear mounting plate, I may just simplify my situation and drill two holes...