Your engine was designed to use one temp thermostat and NONE OTHER. Some guys use lower, but this is basically a high performance mod (sometimes), and has a real downside. If it's a late model, it's like 195* - keep it.
But you can 1) use a "better" t-stat, like a Robertshaw, 2) get a biggger radiator, 3) a better water pump (like a Flowcooler), 4) get an auxiliary oill cooler, or any combination of the above. In truth, the most effective is a bigger/better radiator.
Lowering the temp on the t-state will not keep you from running hot, it just means the system will "turn on" sooner, but once your running warm, the higher t-stat would be full open anyway.
Sorry if this sounds like a rant, but it bothers me that some people (not you) tell others to swap the t-stat when they don't understand what it really does.
OR - just don't use the A/C
'82 Scrambler - NV4500/4.5" lift/33" Toyo MTs/4.0/twin stick, and my windshield washers work! Full 1/2 cab Cage
2004 Grand Limited 4.7 HO - OH Boy!
2010 Grand Laredo 5.7 Hemi - SICK - work vehicle -gone - replaced by an 08 Tahoe - nice ride.
"Both my Doberman and my Jeep can accurately be described as 'black and rust.'"
"I got a fever . . . and the only prescription is more cowbell"