I bought a new heater core for the Camaro several months ago, and I've been postponing installation, just because I've done it before and it's no fun at all. Well with temps predicted to be in the 20's and 30's next week, I decided I was not going to drive around on sunny days with all my winter clothing on.
I pulled the Camaro out of the garage this morning and began the task of removing all the internal duct work, and the heater box under the hood. I was also afraid of working over the freshly painted fender, so went to the parts store and bought two new fender covers.
The core replacement hasn't gotten any easier since the last time. I redesigned my heater box under the hood last time, as I couldn't get it off behind the BBC engine. I cut it down the middle vertically and welded a overlapping piece of sheetmetal on the right half, so I could pull it without removing the fan side. I also opened up the holes for the heater hose connections, to make them notches, instead of round holes.
That paid off this time, as I was able to pull the right side off from under the hood, and then get under the dash and pull the heater box. I then went back out under the hood and removed the clips by reaching through the opening and then back inside to remove the core and set the new one in. After that it was just replacing the clips, and with a little help from my wife I got her to hold the box against the firewall, as I reinstalled the clips and cover.
I had put some black foam tape on the overlapping joint, so I cleaned that off and replaced it with new also. Took about 3 hrs., and it's no fun, but that's better than the all day it took the first time around years ago.
Hope this is the last core I change! I think I actually broke it when I was replacing motor mounts, as I wasn't carefull when I raised the engine, and it touched the outlets pretty hard in the raised position! Anyway, it's nice and toasty insde the Camaro again!

 

Hardest part to change on an early Camaro no doubt.
If memory serves I had the fender half off my '69 to swap a heatercore.
What a big PITA!

 

damn, so its going to be that hard if and when it goes on my 78 i guess lol

 

I pulled the heater core out of my 69 a couple of years ago. Everything came out from under the dash, and didn't have to remove anything under the hood. Took about a couple hours.
And 1971, quit whining about your heater core job.
I just recently replaced the core in my Vette, and I had to dismantle the entire dash and everything under the passenger side to get to it. Took me a whole weekend. Now that I've done it once, I could probably whiz through it in one looooong day.

 

Might be the best way,I was swapping in a big block heatercore and box in mine.

 

Sure seems like one of those parts that was just poorly engineered in every car. They could have easily made it accessible with an access p[anel, and then have a flange on the core that mounted it in place.
That might have added a few dollars to the original design, but it sure would have made life easier!

 

I'm sure you know, that many parts on a car aren't designed for easy on-easy off. Especially one that "might" not fail, or at least not very soon. But when it does, it's past the warranty period and the owner is on the hook for the cost of replacement anyway. And on my Vette, going crossways under the dash (in the way) is a conduit of wires that is at least 1.5" in diameter.
It's a conspiracy, I tell you!

 

Yea, I know their theory. It was a major topic of distraction way back in 1969 when I was a student at GM training center here. Seemed like everything we covbered eventually ended up in a discussion as to "why the heck did they engineer it that way?" topic.
Eventually the instructors stopped any such distractions by saying, "and don't ask me why they did it this way."

 

Lol,they get much worse on the newer cars,changing a light bulb for the heater controls on my '93 is beyond insane so I'm living without it for now.
You have to pull the windshield pillar covers and then tear the dash all apart,just plain stupid!all for one little light bulb that could have had a screw on cover to get to it...........

 

Was that the one in Tigard at 99 & 217?