[bhill86]

I’m really trying not to beat a dead horse, especially as of late, but I also didn’t want to hijack anyone else’s thread.

My 77 T/A has a ‘69 400 in it. Nothing crazy about it. Milled 6x4 heads with 8.8 CR, Comp XE 262 cam. I’ve never had a problem with engine temp in the past. I’ve had it for 11 years. Not sure what kind of radiator is in it but I don’t think it’s aluminum.

In preparation for adding A/C to my car this year I got curious about actual temp compared to my factory gauge this year so I installed a mechanical gauge temporarily. Turn out my factory gauge was reading high due to the sender and my engine was only running around 160° at idle and in town and near 170° on the expressway. I live in NW Ohio and I do drive the car with temps into the 50s so I thought that engine temp might be too cool. I swapped out what I found to be a 160 tstat for a 180. Even on 90+ degree days, my temps stayed around 180 idle/in town and 190 on the highway.

Now I’ve added A/C and the temps above with the 180 tstat are consistent with the exception of at idle. They creeped up near 210 once. As soon as I start moving they drop. I realized my fan clutch was a standard duty so I replaced it with a heavy duty this weekend.

Today it’s about 80° ambient. All was the same as above except at idle which still crept up to 200-205 at idle before I shut the air off and took it around the block to cool it off a little faster. It did take a while, maybe 8-10minites, to get that warm at idle, longer than with the SD fan but, I still feel like I’m missing something.

Before I throw parts at it I wanted some other opinions. The thing ran as cool as can be on the hottest days so I was surprised the A/C made the difference it did.