I have an answer for you. Unfortunately, I cannot confirm what new shocks you need for your 2004 Thor Wanderer unless I have the length of your shocks totally expanded or totally compressed. I went ahead and attached a picture of how you take the measurement of your shocks.
With your 3500 pound axles, I recommend the Lippert Bolt-On Shock Kit w/ Heavy Duty Gas Shocks # LC281255. These shocks have an extended length of 13-1/2" and a compressed length of 8-5/8". In order to know if these... view full answer...
For your triple axle trailer with electric brakes, I recommend the Prodigy P3 # 90195 along with wiring harness # 3035-P for under your dash. This will work well with your 2004 Ford F-450 and is easily adjustable to fit your desired braking with 3 boost levels. view full answer...