Overheating “slightly” and infrequently

[Raider L]

@79K15HIghSierra,

My '74 radiator finally died. It was the original which had been overhauled several times since I've owned it in '81. It was original copper/brass. To replace it is over $250. I got one of those all aluminum custom ones for $150 and now my engine runs about 20% cooler than that old one. The new alum. ones are by far a better rad. I would suggest you spring for the alum. one I think you'll like it, unless you really want to stay with the stock rad.. If that's the case just get it overhauled. These days though many rad. shops are getting away from lead rad's. because of the EPA. If you try to find one of the new kind with the plastic tanks they will cost you as much as the old new copper/brass one you've got.

I went through a month everyday and night trying to find one that had a three core. It was a nightmare. All of the ones for a 350 were a single core. After a month I finally found a three core but it was for a '86 Pontiac big block 422 c.i. IO was so far out of trucks and vans it wasn't funny. I did keep all my notes though so if you need some help finding one let me know.

 

[75gmck25]

I used a Jegs Champion CC161 all aluminum radiator with a 17” core in my ‘75 K25. They also have models to replace the taller 19” core.

Temps are extremely stable with this radiator. Driving on the highway at 70 mph or idling in the driveway with A/C on will make the temp change less than about 5 degrees. I use a 195 degree high flow thermostat, and I don’t think the engine temp has ever reached 200 degrees.

Bruce