I bought a 4-horse Circle W gooseneck trailer last year that has been converted to 2-horse with a camper. It was a good buy and the camper looks like it was a professional conversion. Gives me a place to get in out of the rain, spend the night on long hauls, hot water and a propane stove.
Anyway, it sits too low for my 2005 Dodge dually. With the gooseneck adjusted all the way up, the trailer still sits at a pretty steep angle. It's ok for short hauls, but I wouldn't want my horses to have to stand at that angle for an all-day haul. Additionally, I have to be very careful not to get gooseneck rash on my truckbed. I have barely 6 inches of clearance on level ground back near the tailgate and the rear of the trailer is barely 8" off the ground. The rear axle often hits the floor of the trailer when I hit bumps in the road.
After taking various measurements and jacking up the rear of the trailer, it appears that doing a spring-over conversion on the 2-3/4", 4"-drop axles will provide 5" of additional height at the wheels and pretty much level the trailer. That makes the rear of the trailer about 17-18" at floor level at the loading gate. Pretty high for loading and unloading horses. The trailer has a gate, not a ramp.
Has anybody done anything like this before on a horse trailer? It is a common conversion on gooseneck RV trailers, but I've never seen one on a horse trailer. One thing about this conversion is that it's easy (relatively speaking) to revert it back to the under-spring fit, if necessary.
Mostly my concern is getting the horses to load and unload safely at that height.