What chip comes in the '870 ECMs in the 1985 cars with tuned port injection. Is it the 2732A? I have mine right here, but I can't read any numbers because they are covered by a plastic shell that helps keep it in the socket. It does have 24 pins (4 plastic legs of 3 pins on one side and 6 plastic legs of 2 pins on the other, though the pins are evenly spaced apart.)

 

I've answered my own question with some research. To anyone who is wondering, the '870 ECM has the 2732A prom which has 24 pins and a plastic shell.