Regarding NOS GM heater cores, my experience has been that they were junk from the factory. MY original heater core failed in 1972 at 40,000 miles. I replaced it with an aftermarket heater core that was much heavier than the GM part.....
I don't remember what the brand was but it has lasted for 47 years so far and
130,000 miles. I do know that the heater cores being offered for sale today weigh
about a third of the weight of the replacement I bought in 1972. The last time I
had my car all apart for a refurbish I was going to change out the heater core
just as a precaution, but when I compared the new one to the old, I put the old one back in, it was obviously made of much thicker metal
|