engine still not cool enough

Is the Jaguar clutch you installed a HD unit or a standard unit. As I said in another post on here, my experience with the heavier 7 blade fans is that the std duty clutches will not spin the fan fast enough at idle (to much slipage) and it tends to cause the engine to warm up at low speed/idle. I had the same issue. Now I run the same fan (7 Blade fan) and HD clutch and even on 90* days with the A/C on my cars sit right at the thermostat opening temp while at idle. The clutch is the only change I made and it corrected the issue I had that was exactly like you describe. This is using the assumption that the rest of your cooling system is in good cond.