Heater Core Replacement Problems

Replaced the core on my '67 with AC and went to test it and it blows through the floor vents only. I've checked all the vacuum hoses and they are all hooked up. The switch diverted air to the right place before I replaced the core.

Do the vacuum diaphragms need the car running to be able to activate and divert the air another direction? I've looked everywhere and can't find out. I don't want to hook up heater hoses and fill with antifreeze and learn it's still messed up and will have to be drained again. I've got the water pump bypassed now so I can start the car tomorrow and test. Just wondering.

And I've tested it so far without starting the engine. Just turning the key and moving the switched back and forth.
I didn't get any help on mustangforums.com so I'm asking here as well. Thanks!!

Thanks for the heads up. I finally got everything finished and test drive it yesterday. Everything works great. I did a lot of maintenance besides the heater core too. I've found that some parts are heavily overpriced from our mustang suppliers compared to auto parts stores.

Three years ago when I first replaced my heater core I paid $37 from mustangs unlimited. This time the price is almost $70 for the same cheap core. The price has doubled for some BS core just because they felt like raising prices.

I went with an aluminum one from O'Reilly for $25 and it works just as well.