Replaced heater core, removed a/c evaporator, made car a/c delete , complete, someone took the rest of it off... i got the evaporator out, looks pretty clean without expansion valve sticking out!!
My heater core had me pull "the box" as well. Since I'm in the Deep South, the green dye on my evaporator made me replace it instead of deleting it. Everything else A/C is off the car for the moment but I hope to have it functional again before the heat shows up.

Don't get me wrong, windows down cruising is OP, but so is flexing A/C at a red light on a Classic. lol
Looking for one problem when it laid down found many, but that's how she goes. Back when I thought I had ignition problems I found the spark plugs hadn't been gapped. As in some plugs had no gap. Really, really strange for the engine builder. So lately, we've got new plug wires, new coil, properly gapped (8) plugs, vacuum canister for the brakes, found a broken vacuum cap doing that, and I've been talking to Grok. It led me to the vacuum canister and told me to lean out my choke settings. Now it will crank cold with a couple pats to the throttle before hitting the key. Wild. My studies without Grok told me I needed more fuel from my accelerator pump. Bent the linkage a bit and oh boy. There's a tiny stumble, but son, all she needs is a tiny bend more.
Boys. The Mustang is running like a top. When I say that I mean that it running the best it ever has. This was my daily as a youngster. I didn't trust it for more than a 50 mile round trip. I've put around 100 on her in two days. My confidence led me into rain and then I found out the wipers didn't work. Turns out the nut backed off the wiper motor to wiper linkage? Tightened it up and it happened a couple more times. Young me replaced the wiper motor when it it went bad. Any suggestions? Probably missed the fact that it's a locknut or something.
Man. That was a long post. Uh, thanks for coming to my TED talk I guess.
It's hard being dumb, but onward I push.