blue/black 202 cranks are counterweighted like that. Makes em a bit heavier than red 202 cranks, so some prefer the early crank for quicker throttle response for circuit racers. I'd personally not care about the small gain there and prefer the later crank for slightly improved longevity.

I asked the same thing in the thread bout the counterweighed
crank and must be forged too? anyway the black and blue late
engines also have the 12 port head?
Holden almost had a good engine! alloy head though would have
been great option but not with their casting skills I suppose.