I don't think there's a reliable listing of which HD LIL is on which TP, but a trick I have discovered is this:
Tune your HR20 to a HD LIL channel, then key in another HD LIL - this will put both sat tuners on HD LIL channels. Now hold Info for 3 seconds until the system info screen comes up. Then run a system test. In the system test, you'll see the signal strength for each sat tuner (and each OTA tuner). This won't show you which TP, but at least you can get a signal strength reading for the TP that your HD LIL come from. Note: you cannot record while running a system test.