OK have an 88 IROC and the heater is just a little....lot weak. I was just wondering if there is any kind of aftermarket solution or replacement for the heater core perhaps an all aluminum one, that would make the heating system a little bit more efficient. Now that it's cold I can barely get the heater to warm up when the car is moving...when it sits still for a little while it heats up nicely, but once I get going, the heat gets going too..I'm tired of freezing my *** off. Can this be helped or do I just have to start layering my clothing more effectively?

 

It might be the heater core is blocked, they tend to sludge up after a few years.
I assume the thermostat is opening and closing ok?
Just done one on a Daewoo , it was freezing inside the car, and running on choke a lot, all due to a £10 thermostat.

 

If the fan blows good still, I would start with a heater core flush.