Thanks for the info kymooses.
It is getting tricky to follow these Hood River axle mods. I have spoken to a dealer here in Canada who has the new 2107 blue HRE 180 Rpods but still have the 4 inch riser with the door one step. I have seen (on line) other blue HRE 180 with 2 steps and no risers, but likely do have the 3 inch crush tube. (as described by kymooses)
And then there is the 2016 (December) Green HRE 180 that I am currently negotiating on that has no risers and the one step but does seem to have similar clearance to my HRE 171 with the risers.
I guess the bottom line is that the HRE 180s regardless of the year have extra clearance than a non HRE. Some to do with the axle/riser but also because of the bigger tires.
Be interested to see the height from pavement to bottom of the frame on these 3 recent but all different types. I'll have to go back and measure the HRE 180 that I am dealing on and measure. But I can say my HRE 2015 Rpod 171 with the 4 inch risers measures 16 inches from bottom of frame to pavement just in front of the tire with the trailer level. The 171 tires are 235 on 15 inch rims.
I want the best height I can get so I don't loose a stabilizing jack going up an abrupt incline into a gas station etc.
Bob