Yep, to use a dentside front swaybar you'll also need to use the donor trucks radius arms, which are slightly extended forward and are notched to properly locate the swaybar mounts. The alignment pin is built into the swaybar mounts. Here's a couple comparison shots. The first picture is of a standard bumpside-era radius arm. Notice how they're flush with the front of the I-beam:
...and here's a shot of the dentside-era radius arm. You'll see how it's extended with a notch for the swaybar mounting bracket:
Here's a picture I took of a mid-'70s Ford van in a local salvage yard, that shows the relationship between the mounting bracket and the notch in the end of the radius arm, and is virtually identical to the truck setup. (I just didn't have a good pic of a truck layout to post.):
