i can see it on the addco kit but I'd only be guessing the placement and size of tab, or are there any cheap aftermarket OEM control arms with tabs out there?
Actually I think the older ones are harder. The tab needs to be bent in a little so it doesn't hit the front lower ball joint bolt. It's sort of the same tab, with the legs bent in so as not to hit the lower ball joint bolt.
To make a 73-76 tab:
Get some 2" x 3" square tubing or 2" x 3" channel.
Cut the end across the 3" side diagonally 3" back to make a 45 degree cut.
That will leave you a channel cross section that is 2" wide with two 3" tall legs.
Cut those two legs 3/4" back from the tip to make the legs 2 1/4"
Drill a 5/8" hole centered 2" from the back of the legs
That mount will be about 1/2" lower than stock. Not a big deal, you can just run a shorter end link spacer to compensate. You want to set the sway bar arm level to the ground at ride height. That will also be level to the sway bar tab. The factory tab is angled down slightly toward the center of the car. The angle is relative to the LCA flange.
I just made one out of cardboard
You could make the piece out of 4x2 square tubing or 4x2 channel and put a notch in it like this. That would put them more at the factory height, but they are not as simple to make.
I forgot where I got these pictures. But I think the top one is installed 1/2" lower than stock. Like it's not taking advantage of the cutout on there.