I believe the highest I can recall seeing the needle go is halfway between hot and the halfway point, before we turned on the A/C, which brought it down to "normal" operating temps.
As far as the LIM gasket, does that present itself solely as an external leak, or, does it leak into the crankcase, my question being: wouldn't I see evidence of coolant in the oil? No, I've never had the LIM gaskets replaced.
I intend on replacing the the thermostat, if for no other reason, at least it will fix the leak.
Thanks again for your responses.