I think that should be kdelibs4-devel.
@alansecker. Your post doesn't hint so much on where you are stuck at. Also we are now at 64-bit Test 4 and as someone using this "not-yet-ready" 64-bit PCLinuxOS, it is advisable that you install the latest test ISO. The tests for 64-bit will take time but it will be ready, just not for Test 3 that you have installed.
Whatever your project is, and I am assuming it is a simple installation of an app that is not available on the official PCLinuxOS repository, only you can really say whether you want to pursue this or not.
Otherwise, you can always forward a Package Suggest and hopefully one of our still-very-busy packagers might take the time to look at your request and package the app for you.
Good luck.