You need to know the exact make and model of your Chevy (e.g., Chevy Silverado 1500, Chevy C1500, Chevy Tahoe, etc.) to determine compatibility. Even within a model year, different trim levels might have different transmissions.
Further complicating matters: even if the transmission *physically* fits, you'll need to consider the computer compatibility. The 4L60E's electronic controls need to be compatible with your vehicle's PCM (Powertrain Control Module). A simple bolt-in swap is unlikely without significant modifications or a custom tune.
In short: Don't assume it will fit. You need to research the specific transmission your Chevy came with and cross-reference that with the specifications of the 4L60E you intend to install. A local transmission shop or a reputable online forum dedicated to your specific Chevy model is the best resource for confirming compatibility.