Classic Winnebagos & Vintage RVs

I was reading a similar thread in a different forum about checking the roll of the camper and changing the old rubber sway bar rubber to some new urethane bushings.
Well I checked my camper out and being a 1979 Itasca winnebago  on a GMC P30 chassis,  it could stand to have the rubber bushings replaced.  In the other forum their sway bars were only 1" in diameter.  My sway bar is 1.75" diameter.   This is the heaviest sway bar I've ever seen.
Does any body have any ideas about finding bushings this large?

They are available, I replaced mine (1.75) With the urethane , Did not notice any improvement but developed a clunking when the bar does its job . I am going to replace them with the rubber ones ! Frank

Do you think the clunking was from the urethane bushing having some play around the bar ?

Update.
I installed the urethane bushings after cleaning up the sway bar and repainting it. 
I used the grease that came with them, I did get in touch with the manufacturer who told me that any silicone based marine grade grease can be used.
We went camping last weekend and my daughter was following me in her car and told me the camper didn't sway back and forth like it used to.  I did notice that I didn't have to saw the steering wheel going down the road like I used to, and we were driving on some very winding back roads.
I didn't notice any clunking going down the road like Froggy mentioned.
So all in all a very good upgrade.