Please do not trust some of those Youtube videos saying you can replace the heater core on all Gen 3 Firebirds and Camaros without taking most of the dash apart. I have a mint 1988 Firebird V6 AC delete. I should have read more on this site than going by the Youtube videos. First I see that my 1988 is slightly different than pre 1986 and also different than the 1990-92s. There is no way you can remove it from underneath the dash only. To protect my mint interior I took the top dash pad out, took the radio console out, took the lower plastic trim off, lowered the steering column down, dropped the dash down about 6 inches and out from the firewall about 6 inches. After doing all this, I was able to get at all those hidden and hard to get a screws out that removes the cover over the heater core and then 4 that holds the core itself, one that is really hidden. Most of the Youtube videos never actually show the core being removed, they just say they did it from under the dash. After reviewing them again, it looks like some of the cars are being butchered into race cars and the authors just post them in the hopes of making some money off clicks. Glad to say my Napa replacement core fit the holes perfectly. I hope this comment saves someone else some time if working on an 1988 Firebird.

 

Thanks for sharing that.

Having just had some of my dash apart, I dread the day that my core starts leaking.

 

I did a dash swap a few years ago...since the dash was out, I swapped the original heater core at the same time as preventative maintenance.

Should be good for another 15 years with no hassles.