Most likely used on later thermoquads. Never seen that part in a 72-74 thermoquad. Heck I don't even remember it in the NAPA kits I used for rebuilding early TQs but it's been a few years.

1970 FE5 Duster 360/904/3.91's SOLD 1973 TB3 SpaceDuster 340/4spd/4.10's SOLD Moparless for now but when the opportunity is right I'll have another one.