So here is what I've found in looking at pictures of 70 Boss 302's. All except the very very early examples with the loom routed to the hook attached to the upper left heater motor attachment stud and routed between the heater hoses.
57th Mustang assigned a VIN at Dearborn and a Boss 302; One of the cars built for show car duty around the country
Has the wire loop wire retainers on the passenger side shock tower support
Spaced out the remaining through the production year rather than show the dozens of individual examples
Upper left - 0F02G1163xx
Upper right - 0F02G1421xx
Lower left - 0F02G1697xx
Lower right - 0F02G1907xx
Going to look through the other 70's to see if we can find how the routing of that loom was related to options or engine size on other models