I've recently picked up a 2008 4.4L - maintenance records and the volume of work done were impressive, and it came pretty cheap, but the rear crossmember and/or bumper reinforcement is thoroughly rusted. I see they're available online (very limited), and I'm perfectly capable of bolting and welding one on, but my question is this: if I replace the rear crossmember, is there anything else I need to replace while I'm at it? I'm specifically wondering if there are other bits that go along with the crossmember itself for towing, etc. I do some light towing with the vehicle, a 20' boat a couple times a year ~80mi each way, so it is important to get it structurally sound for towing.

Second question is: will the rear crossmember of an LR4 or RRS be the same part, or do I need a specific LR3 part?

 

Answered my own question for #2 - the answer is yes, compatible.