I'm guessing you're probably thinking of the ZV9 baseband update. These files update the radio on the Optimus V, and some people think they improve call quality/ data speed. DO NOT PUT THIS ON YOUR SLIDER! First of all, it wasn't made for it and I could easily see it bricking your phone. Second, I don't think it can be undone. In general, you should only flash roms recoveries and mods that were built/ported for your phone.
My brother has the slider, and unfortunately there isn't anywhere near the development community behind it. There is a forum on here for it though. Check it out:
Virgin Mobile Optimus Slider - Android Forums at AndroidCentral.com