Wow... that's interesting. It's less CCs?? The head is supposed to be better than the 22s?
Gnarls.
Yes, that is why people use the 20r head on an early 22r block to make a hot dog, 20r/22r hybrid 4 banger. My machinist measured them side by side and the 20r head has smaller ports, but they are round and have a better shape for flow. He said this design typically makes more torque because it keeps things moving faster. The 22r is more of a swirly, tumbley flow for emissions.
I can tell you I have both engines in trucks right now and the 20r even with the stock bottom end just feels a bit more peppy and definitely has more pull up hills. It also wants to rev higher and doesn't have that tight feel over 4,200 that a stock 22r does.
Now we are talking early carb stuff, mind you, with the different block.