Howdy yall, I`d like to introduce myself, my name is John, I`m from southern New Jersey, I`m 33. I am a chevy man through and through. Right now I have 3. A 1971 short bed 4x4 fully restoured hugger orange (show truck), a 2003 black z71 avalanche(daily driver), and a 1988 k5 blazer W/4 in springs 33x12.5 tires (hunting/4wheeling truck). Now the reason for this post is I am having problems with my 88 getting hot. It has a 350 tbi with a 700r trany. It also has a throttle body spacer. I just installed a 180 thermostat to try and fix the problem with no results.It only gets hot when I run it on the highway. Last night I went about 7 miles at 65 and it was about 225-235, when I poped the hood the passenger side exaust manifold was glowing red...The timing seems to be ok and the anti freeze is toped off. Any help or thoughts would be great.