The Heritage info does not state a RPO for Ebrake but shows it on PP 117 as standard. Rods and cables or on-drum, depending on model as Bill states.
Once you see how it is all mounted, you will probably discover some provisions for it on your truck if you have a stock frame. Some are riveted on and are unlikely to have been removed. You can also acquire the parts from time to time on Ebay. Don't see a pic of truck in your signature.


Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn