There will be a short straight section close to the large hole, which is what I'm putting in here. I picked up the location of smaller hole first and then made these two cuts.
 

Now it's time to rough out some material. And to make sure I don't cut in the wrong spot, I'm using some layout dye and then scribing a line from one hole to the next. Now these holes are not inline with each other. The reason is because this section will end up with a taper, just like a real connecting rod is designed. Once the material is removed, they will blend at both tangent points (the holes I drilled earlier).
 

Time to put some holes in for my rod bolts to pass through. These holes are .250" diameter (1/4) which will fit the same size bolts without any slop. I could have made them larger but there's really no need.
 

Here you can see the material roughed out along the taper. If you look close you can still see the scribed line I made earlier. I'll  be finishing this area next.

What I'm doing below is putting a small line across the big end of the rod to simulate it being two pieces. There was no need to actually make a two piece connecting rod because it doesn't have any real function, other than looking like a 'real one'. This line is only .005" deep and was made with a 45 degree carbide end mill.
 

To make it easier on myself, I made the angle or taper at two degrees. That's the nice thing about designing something yourself, you can do what you want.

Now there are a few things going on here so let me explain one thing at a time. I'm using my 5" sign bar to produce my angle of two degrees and it's being clamped down with two clamps (A).

The two larger clamps (B) are holding down my work piece. And to make sure I don't damage my work piece, I've placed some aluminum shims between the clamps and connecting rod.

To attain the angle that I needed of two degrees, I would need to use something.174" thick, and I just happen to have a parallel that exact size (C). This is what you see between the sign bar and my mill stop. All this for my two degree angle .

Once everything was clamped down, I used my 1/2" end mill again and carefully removed the remaining material. The hard part about this kind of setup is making sure to not go farther than my tangent point, or blend point. If I did go farther, you would see it as a dig-in spot where the cutter removed material were it wasn't suppose to. Taking your time is key here.
 

Now it's time to work on the smaller end and that will require the use of my rotary table. Now I could have used my belt sander and worked the rounded shape to a scribed line. However, that process wouldn't look as good as the one I'm doing here. On the other hand, the belt sander is very quick and this one is not.

It's been about four years since I've use this rotary table and come to find out it wouldn't even turn. I had to use WD-40 along with some light oil injected into specific areas to get it to move at all. This wasn't good news because I will have to turn the handle on it many many times. Once I had it loosened up somewhat, I placed my work piece on it, indicated it in and then clamped it down.

As I was turning the handle, I quickly found out that I still had rough areas within it, making it hard to turn. Now this handle doesn't spin which compounds the problem, so I put on some cotton gloves (the ones I like to weld with) which made life much easier for me. Side note: this is the first time I've ever worn gloves working on a machine because they can be hazardous. On the other hand, I wasn't near the moving spindle or cutter either.
 

The trick to doing this is to not rotate the table to far or I'll end up digging in to the beam of the connecting rod. It's the same thing as before, work slow and don't mess it up. I'm glad I took the time to machine the end like this because it's perfectly round and square to the sides. There's no way I'd have it look this good from my belt sander.