Change the size before you insert the PSV on your drawing, thats it.
Best Regards,
Pat Andres
Autodesk Expert Elite
Plant 3D Administrator
GHD Manila
Oh sorry, i misunderstand your problem. For your information, the PLantpartconvert of 2013 and 2014 is almost the same, you must first select the block then on the custom part tab, you will assign the size, the end point connection and the rest of the properties. I dont know why your plant 3d behaves like that, but if in any case, it doesnt change its behavior, may be assigning the porst after blocking it, then "IMPORTING IT IN YOUR CATALOG AND THEN YOUR SPEC" will do much better. In anyway, having it in your catalog and spec means you can use that PSV or whatsoever custom part you have made over and over again as much as you like, not like what you will have on "CUSTOM PART" command. Thanks
Best Regards,
Pat Andres
Autodesk Expert Elite
Plant 3D Administrator
GHD Manila