I generally don't like that site. Tries to do too much at once, with few if any expertise demonstrated. Feels something other than American too, which doesn't impart confidence.

Anyway, my impression is that the Super Commando was the HP engines. Since the 4bbl. 383 was reduced in compression in 1971, and since there was only one 383-4 for the year, I think Plymouth dropped the engine designation. JMHO.

But look at this:

https://www.npdlink.com/product/dec...r-cleaner-correct/173522/90170?year=1971

Is that a 1971 'Cuda 383 air cleaner decal? If it is, then there's your answer.