Here is what you really need for your TRX-4 to get the max capabilities for the money. I do have 2.2’s with Swamper 5.25’s and cut the wheel wells to clear with just a tiny bit of rub every here or there. I have every piece of brass on the front except rod arm and shock mount axle supports and axle, no brass in back.
Traxxas Rod arm link part number is 8149