Those are common truck, van, motorhome covers from the 70s. I have several pair. They usually have a good sized sticker on the driver side top with all engines available that year and a hole punched that identifies the engine they are on. All kinds of widjits are welded on them to hold wire looms/holders or whatever. Probably not the best choice for an RB A body application if clearance issues are a concern- sometimes they wont even fit a pickup if it has the large diameter brake booster. I have some with exhaust heat shields on them.
