IMPORTANT: Follow my instructions carefully when dealing with the impact struts otherwise you’ll never get these sons of bitches installed! Trust me.
Install the impact strut mounts to the factory crossmember with the supplied 3/8″ x 5″ bolts, nuts, and washers. Locate the holes in the center of the impact strut mounts. Using a drill with a 7/16″ or 1/2″ drill bit, carefully drill up completely through the transmission crossmember (yellow arrows). Install the supplied 3/8″ x 3″ bolts, nuts, and washers with the bolt head facing down and the threads facing up and leave them loose.
Now loosen the four bolts that hold the transmission crossmember and impact strut mounts in place. Do not remove the bolts – just loosen them. It is important that the impact strut mounts have as much movement as possible when trying to get the impact struts installed, hence the reason we’re leaving everything loose until the struts are installed.
This is what the impact strut mounts should look like at this point. If you look closely you’ll see that it’s not up tight against the transmission crossmember. It hangs down about 1/4″. You need this 1/4″ of slack in order to fit the impact struts into place.