I have the heater core out right now and I am wondering if I should replace it now while it is out. It appears that it is the original. My guess is that it would have the same failure modes as a radiator (clogging and cracking). Should I replace it or not?

 

I would they are not too expensive.
Also buy the heater case gaskets for like 8 bucks and redo all those too. It makes a huge difference in airflow

Gun

 

I agree, if you've already done the labor I say replace it. Cheap insurance.

Justin

 

I've taken mine apart twice in the past 7 years, and as the heater cores are about 22 to 23 dollars, I have just replaced them each time as cheap insurance. Last time was two months ago and I modified the intake and dischard tubes to extent through the firewall so that any time I need to remove or replace heater hoses, I can do it from the engine side of the firewall. As I have those hoses covered withe the fake connectors and the stainless steel mesh, You can't tell that i did the mod.