Question on converting Lionel CA-1 caboose to 2-rail

There would only be one way to find out....

But since it was an MTH car, it might not be a surprise if it still had MTH trucks.  Probably worth pulling an axle, taking the measurements and comparing it against the axles NWSL sells to see which one is the right one.

Does that CA-1 caboose have rotating bearing end caps?  Those 2 rail wheelsets are for rotating bearings.

I converted a Lionel NE Caboose with Atlas caboose trucks before lionel was making the 2 rail wheelsets.  Was very easy.

I'm not sure what I did wrong, but I tried using this conversion kit for a Lionel N5b PRR Cabin and the needle points on the axles are too long compared to the three rail wheelsets I pulled out. 

Just my experience on that specific cabin. 

On both Lionel and MTH cars, I have  used AThearn or Intermountain Wheelsets.    sometimes they are a little loose in the Lionel trucks and sometimes not.    they tend to fit the MTH trucks better but work well in both.    These axles are about 1.795 inches long.    So something in the range of 1.800 long seems good.    All the ones I did are needle point for solid bearing trucks.

Thanks for the feedback, everyone.  Since I have some Intermountain wheelsets on hand, I'll try those first and see how they work.

Could you purchase 2rail version of the trucks from MTH or Atlas?

The Lionel caboose still uses the same MTH trucks so I would try to look for MTH 2 rail wheels rather than Lionel.