Yes, 67-70 rivieras had studs on the forward oil pan bolts to attach the battery cable as it had to wrap around behind the harmonic balancer and make its way to the other side of the engine.
Wanted to post a follow up because I finally found an image from the service manual of what my motor is missing and how the oil pan stud bolts function. This diagram below is buried in the electrical section which I guess makes sense now. The oil pan stud bolts do indeed hold a plastic tunnel for the positive battery cable. The "tunnel" is housed in a metal bracket that fits over the plastic piece. Last time I would have seen mine would have been in 1985. (I bought the car in 1983). Chevy also had similar ideas about supporting these cables but limited their dressing to clips. Oldsmobile had a tunnel and the ones I saw seem to be made from phenolic. Neither of these manufactures separated the positive battery cable from the wire harness like Buick had. In the pictures of my engine below, you can see how the studs most probably fit on the inside of the bolts for the metal bracket that protects the plastic piece. I figure if I still have the pan studs and at least one of the bolts that would hold on the metal bracket, this stuff was probably on the engine when I pulled it for rebuild in 1985. In subsequent years and moves, these parts disappeared. I vaguely remember these parts and only because I remember cutting off my fusible links when I put the engine back in the car. Going to post on the board that I'm looking for these and see what comes up.
Nope....the wiring gutter uses the two small 1/4-20 threaded holes in the side of the block. You can actually see one of the original bolts in the block. They say "sems", have an integral star washer and are very short
