I changed the thermostat (160) out again for the 4th time and replaced the reservoir and cap, replaced the water pump and bleed the system, its not boiling over so much but still running around 210.
However new problem... I was on my way to hollister hills and when towing my jeep on a dolly for the first time with both trans and transfer in neutral (was told okay to do) i blew the casing out... I disconnected the drive line and brought it home as you can see its a goner.
210*F is the "Spec Operating Temperature" for the 6-242 engine, and it's common for most engines these days.
Doesn't mean I like it - I've pulled the op temp in my 88 down to 185-190*F, and it hadn't had any impact on smog results (but the oil holds up better, with running that little bit cooler.)
If you're going to flat tow with a dolly often, I'd suggest a SYE (Slip Yoke Eliminator) kit for the rear output shaft, then just remove the shaft before you pull. The front shaft can be left in place. (You can
use a transmission tailcone plug to keep the fluid in the case, but the SYE is a better solution, and allows you to drive with the rear driveshaft removed, in case it gets hooped on a rock...)
I remember seeing "driveline disconnect kits" years ago (mechanical clutches that went right in front of the axle to connect/disconnect the driveshaft,) but it's been a number of years, and I don't know if anything like that is still available. Thing looks like a driveline brake drum, only smaller.