Yes, all '70-'72 engines used this setup. A stainless steel cup fits in the open hole. The idea was to heat up the choke faster than could be done with the thicker cast-iron wall of the previous choke well cast into the exhaust. The '73 up exhaust manifolds went back to a cast well, but with a (crummy) "electric assist" setup which was a small heating element next to the (nonadjustable) choke coil to heat it up and kick it off. The electric choke kit I linked earlier is a real (and adjustable) electric choke.