If I'm understanding the terminology correctly, the exhaust, including the flange connecting the longbranch manifold to the front pipe(s) is about 5 inches off the floor, tucked up about 1/2 inch above the frame at 4 1/2 inches off the floor. I only measured the left side.

I can't think it would be good to have the exhaust have to absorb the full shock of hitting something underneath.