Making sure you will have ample joint articulation is best determined by driving each side of your truck up an inclination ramp to induce full flex. Even though you application may appear to have steep angles at rest, depending on which way the suspension travels more (up or down), you may be in better shape than you may have originally thought. Below illustrates this condition where you can apply it to your situation...
With both wheels on the ground the drag link joint angle at the axle knuckle is 11 degrees while the pitman arm is also 11 degrees. In this illustration the pitman arm "pad" (where the joint connects to) has a 3 degree angle.
With the passenger side wheel raised 10" and the driver drooped 10" the knuckle joint angle is only increased by 6 degrees, well within the operating range while the pitman joint in almost perfect. A Close Quarters Bend™ at the knuckle could correct up to a 14 degree angle if needed
With the opposite side now raised and the other side dropped the knuckle joint angle is almost parallel with the axle, well within the operating range while the pitman joint is at 17 degrees still within the joint's articulation range, but easily corrected by a Close Quarters Bend™ for even more travel if needed.
If only 8 degree Close Quarters Bends™ were used at the top and bottom of the drag link, the worst angles shown above would only be 11 degrees MAX, instead of the 17 shown.
If a Tie Rod Over Knuckle™ kit is used to raise the passenger side axle knuckle connection point for the drag link a reduce overall angle on the bar could be taken advantage of as well.
Here is a Bullet Proof Rod End™ nearing full downward articulation totaling to a full 42 degrees of vertical motion, which results into a full 30" of suspension travel at the end of a 41" drag link.