i run at about 100(start up) to 160(open high way) never really any hotter, should this worrie me?

 

Motor's run the best at their operating temps because they are designed with thermal expansion in mind, too cold will have undesired effects like premature wear.

 

i was told that replacing the thermo, would help run hotter, seem right to you, and whats the op temp on an 87 4.0?

 

approx. 210*...

 

Yes and yes.

 

do you have a "fail safe" thermostat?? on this same note, seein mine is the same temps.. i want to know what the deal is. its only a month old. i should have left the old one in. but i changed the gasket and figured it put a new thermo in too. Opinions??

 

completly stock as far as i know

so replace the thermo, what should i look for to replace it?

mgp increase?

 

It's a possibility your thermostat is stuck open, however if it's possible to get your hands on a laser temperature gun, verify the temp reading on the thermostat housing. Our Cherokee gauges, especially on our older renix jeeps are notorious for being inaccurate.

 

ahh, renix problems...lol