Mine had the large 4 on the cover, not as neat as some. 1978 W72 Auto 3.42.
Also, the various inspection squiggles and dabs in different colours on the casting and leafspring perches. You'll also notice at some point a coating of black underbody spray, basically along the rear of axle tubes and cover where they waved spraygun under car.
Diff cover inspection paint 342 78 manual by
Aus78Formula, on Flickr
342 posi 1978 unrestored1 by
Aus78Formula, on Flickr
diff inspection paint 342 4speed 78 by
Aus78Formula, on Flickr
And this is how it turned out after I rebuilt it. As you can see the bare steel areas came out the wrong colour and almost alloy in shade.
Diff restoration complete axles drums 3_12 10 by
Aus78Formula, on Flickr
Some original low mileage vehicles. Top is a '78 W72 Auto TA. Bottom is a '79 TATA w/403. Has a blue G under it.
78 Trans Am 342 diff W72 twin mufflers sway bar chassis original by
Aus78Formula, on Flickr
79 TATA 403 low miles original suspension diff valve cover label (5) by
Aus78Formula, on Flickr