The third member housing (ring and pinion hsg) is cast. You should be welding your upper tabs to the stamped steel area of the axle housing unless you have a large pinion offset. Then one set may be on an axle tube. You didn't mention what you were installing this on. I would keep in mind that if both sets of links are parallel with the ground, there will be zero anti squat. No lifting or no squatting due to the links. Weight transfer will still make the back of the car drop some though. That is why most setups have the upper links angling down to the front in relation to the lower links. This is just enough to counter the weight transfer. Billy Shope explains this in his writings. The link Itoldyouso gave you has a lot of dimensions listed there. Install lower links first. I would install the upper link that is easiest to do first. I used poster board for templates drawn off the brackets you have in the kit. Trim these to fit and then transfer over to supplied brackets for trimming. The difficult side can then be done by mounting the frame bracket first. Set the link length to match the other side. Make sure the angle from side to side is the same as the other side and tack a temporary piece between link and axle hsg after you have set the angle in the vertical plane the same as the other side. A Smarttool level is very helpful here. Then use your poster board templates to trim to fit this side of the housing. Then transfer over to your supplied brackets. Tack everything in and move hsg through suspension travel before ever welding anything in solid. You may have to fabricate brackets due to offset housing. Study link Itoldyouso gave you. Hope this helps.