Preferring RSVP for only one l2circuit.

I have a full-mesh LDP LSPs between my MX-104 routers, however, between two specific routers and on the same loopbacks I configured RSVP LSP to be used as the transport for only one l2circuit and no more. The problem is, when the RSVP gets signaled, it gets installed in the inet.3 and gets preferred over any other LDP LSP. So all the traffic destined to RSVP tail-end will prefer the RSVP over the LDP. I have increased the preference of the RSVP, and it has been taken out of the inet.3, so the l2circuit didn't prefer the RSVP path anymore! Do anyone has a working configuration for this? or should I configured another loopback address on every pair of routers for the RSVP signalling? -- mk