Track Question - O scale

[FunValleyLine]

I have a new lionel set and it says O-scale on the box. I am looking for more straight track to put a suspended loop around my train room. My question: Is there a difference in O and O-27 three rail track. How do I tell what to get. Thanks in advance, Tom

 

[Trucula]

The difference is the height and only thing you need to add is a shim under the one to make them compatible.

http://trains.com/ctt/default.aspx?c=a&id=544 (see artical copied below)

"The two profiles were not designed to be mixed. They can be used together on the same layout, however, if the O-27 track is shimmed by 1/4 inch and the holes in the tubular rails are enlarged to accept regular O gauge pins."

 

[FunValleyLine]

Cool Thanks a bunch I will shoot for the O so it matches but it will work out if I end up with the other. Appreciate it.