1986 22-RE Running Hot

I have a 1986 22-RE AT IFS 4x4 pickup. I got the truck off of my Dads friend who didn't take very good care of it. Within the first week I had blown a Head Gasket. I've had the head remachined and cleaned up by my mechanic. After a couple weeks of driving it on the fixed head it started to run hot. About a month ago I replaced the thermostat. It seemed to be fine up until a week ago. It started to run hot again, especially when I was either stopped or in traffic. That is when the temperature would fluctuate the most. I noticed within the first 15 minutes of running the engine it would go up to nearly 3/4ths the way. Over the past weekend I replaced the radiator. 21 years running on the stock radiator. The radiator was the correct one for the truck but had a slightly smaller capacity than the stock. It still runs hot within the first 15 minutes. Any thoughts to what it might be?

... I noticed within the first 15 minutes of running the engine it would go up to nearly 3/4ths the way. Over the past weekend I replaced the radiator. 21 years running on the stock radiator. The radiator was the correct one for the truck but had a slightly smaller capacity than the stock. It still runs hot within the first 15 minutes. Any thoughts to what it might be?

That's not an uncommon thing. Toyota used to have a 2 stage t-stat to help fix that, not sure if they still do. Or you can just drill some 1/8th" holes in your t-stat. It lets some coolant thru while it's warming up.

But if it's only for 15 min and the needle on the gauge isn't pegged, it may not be worth it.

H'mm, just noticed you replaced the rad, but no mention of the t-stat. If you didn't replace it too, start there.

Yeah I replaced the t-stat some time ago after the head blew. I'll have to look into getting the dual t-stat. My girlfriends truck has the same problem.