Wow. From what I understand, the part you are doing now is just the prototype pattern for the real part which will be 4130. Of course, aluminum for a pattern is a heck of lot cheaper than that steel. I lived beside a machine shop for nearly 60 years. In the latter years, those guys made connecting rods for racing engines. I believe they were using 4340. Maybe you could find that where you are. That's about as tough as steel gets. Probably a lot more expensive too. Even with a good drill press, when you start drilling holes in the 1"+ range it has to be heavy duty. A company I worked for years ago had one that drilled up to 3" holes. The handle that pushed the drill bit down was like 4 or 5 feet long. She was a monster. You need a Bridgeport and use cutters for those big holes. My neighbor had an indexing table on one of his machines where you could set the circle diameter and drill holes at precise angles. Of course most of his high tech work was done on computerized CNC machines with diamond cutters. He had 7 or those machines.