That’s a federal pump from looking on my phone. All of my 69 cars have the Saginaw pump. It’s a better pump and able to keep up with the pressure needs. The federal pump requires different regulation valves for each different application and they only came that way from the factory. If you got a rebuilt pump, no telling which valve you got. Dragon slayer is the man to talk about federal pumps. The only federal pumps on 69 still were c bodies, Hemi and small blocks. The TA/AAR federal pumps got the same pressure valve as a big c body in 70. Dragon knows more and has pictures. I’d get me a saginaw pump. The square hole you are showing is for a 1/2” drive breaker bar or ratchet to tighten it, not a bolt.
