The panhard has a big effect on how much the driveshaft hits the gas tank skid. The panhard is obviously not the cause of this, but it can push or pull the axle closer or further from making contact. Of course sway bars and extended bump stops will help cure this issue but those both limit offroad capabilities. The higher the the roll center the more swing the axle with have side to side under articulation. Think of a triangle with the top part as the axis of rotation (Roll Center) and the bottom as the axle. If the RC is low (on the same plane as the axle) the axle will rotate around the center of the differential. Now raise the roll center say a foot. The axle will now swing in more of an arc rather than just rotate around its own center. So if the RC is raised (pandhard lift bracket), the driveshaft will actually swing more into the gas tank skid. With the RC lowered (panhard drop bracket), the driveshaft will have less swing towards the gastank skid. Also if you went with just adjustable and no brackets, you would have to extend your PH to center your axle, which actually pushes it closer to the gas tank skid. I know roll center and all those other suspension terms can get confusing. Which it was very confusing for me when I first started learning about linked suspension. If my description doesn't make sense, then start searching to get a better understanding. Hope this helps though.