When I bought the car there were AC lines running through this part. I removed the AC and thought about running the coolant lines through here but they are now under the car.
Installing flares and inner long kit has brought me back to this damaged area .
I looked for this part on some on line diagrams but could not identify it (yellow arrow). It looks like it is spot welded to the outer long and sill.
I am sure it is supporting the the threshold, sill, very well but I feel there is more to it.
It may get cut off today, so I should ask... Is this part reproduced? What is its function?

I also did not find the little support brackets (green arrow) so I started making new ones.
Again, I am thinking of stamping 2.1" holes in the smaller brackets and rerouting the coolant lines.
I am just wondering how much thought I should give to the larger (yellow arrow) part.

Looks like a hack job repair to me...

looks like a forklift fork cut through it in one spot. That's hard to see in the photo.

Hack jobs usually don't include spot welds. The only way to spot weld that on would be from inside the long. It looks factory fit to me. What year car is this?

Its a 73 but both of the front fenders were replaced at some time.
This side has welds the other brazed areas.
The hack did the cutting and bending to a factory installed part.
I am sure to install the A/C lines. Dealership hack?

Here is an other view. You can see the big hole on the sill bracket in the back too.

So, is this part NOT on all year cars?
Do new longs come with this part spot welded on?

that is the A-pillar base gusset to the front portion of the tub. FIX IT!

Thanks Sean,
I believe we met last weekend before you took off from the G&R.

After a lot of digging out body seal, I now see what your saying and why I could not find the end to the part. Looks like the door attaches to that same part. That smaller part is not just a gusset but also runs up to the A pillar.

Now that I have this big hole that needs corrective action, I may have to look into welding a tube in through it for a coolant line.

I think the drivers side is formed so smog lines can fit. I don't know if there is much room for a coolant return line.

Back to work

The holes are typical of a lot of A/C installs. The dents are anyone's guess.