overheating

Newly purchased 1990 YJ 4.2 with a Weber carb. The issue(s): Everything was fine when I did the test drive before buying it. On the way home the temp gauge slowly crept up all the way to just under the red mark and stayed there. When it got hot, it started sputtering and bucking like a bronco...

My 89 YJ still overheating and I have invested thousands of dollars trying to address the issue over the last few years. Replaced the radiator with an all aluminum high performance radiator twice (2 different brands) Replaced thermostat at least 5 times with everything from 160 degree too 190...