210 degrees and \"service engine soon\" light comes on I went to go get our snowplow from our place north of where we live in the '87 Chevy Utility truck. Got about halfway home on the highway (43 miles or so) and I watched the temp guage slowly creep up. Once it started going over 210 the service engine soon light came on. It's a stock TBI 454 with single exhaust and a catalytic coonvertor. I pull over and let it cool down, with the engine running so the fan is spinning, and with the heater on full. I open the hood to let more cooling happen. Something smelled really hot. I looked around in the engine compartment, walked over and looked at the pass side of the engine...thought to myself as I glanced at the manifold, "I don't remember the exhaust manifold being painted bright orange." Then I look back at it again immediately and realize it's so hot the whole manifold is glowing bright orange. For once I was glad those individual spark plug heat shields were still there. So I go shut the motor off and let it cool for a while. After it cooled, I was able to drive the rest of the way home without overheating after I dropped the plow blade down 2 more inches. So, what would cause an exhaust manifold to get that hot? I was thinking the restricted exhaust flow, with the passenger bank being the side that the pipe gets crossed over into the single pipe. Then to add to that, possibly a partially clogged catalytic convertor. And of course, running hot with the plow on the front. This extreme heat would explain why the old plug wires crumbled when I replaced them a month ago. Looks like I'm gonna get to use my sawzall I got for Christmas and do a little exhaust modifications.