I believe there was a factory provision for securing the down pipe to the engine on some years. If you're going for factory originality perhaps one of the parts-book gurus can find a factory part that you can copy.
I'm not a parts book guru by any means but, the Factory Assembly manual shows only two points of support for the entire exhaust system.
The first point of support is a strap around the muffler that attaches to the frame via a bracket. The second point of support is a standard exhaust hanger that attaches to the frame just before the tailpipe turndown.
My truck does not have the original muffler strap and bracket but has an exhaust hanger just before the muffler. The second hanger is in the factory location at the tailpipe.
