Overfill limiting valve

[burdar]

The manual states that if the carb does not support it the plug on the canister should be capped, so the 74 still used a 3 hose canister (Fuel Tank, Carb, Purge)

That makes sence.  You can see from the pictures I posted that there is a center post on both the canisters.  The accual nipple must sit lower on the center one since I can't see it.  Both the 2 and 4 barrel carbs don't have the bowl vent in 74 on the E-bodies.  I think the 2-barrel car is an auto and the 4-barrel car is a stick.  The canister must have been universal for all 74 models.  The center nipple was just capped on the E-bodies.

[Jamiez]

The canister is definitely universal for all of 74, there is only 1 part number listed for it in the Mopar parts catalog 3577 595.