Thanks, that cleared things up.
Now I have another question. I found a 250 locally for a very good price and in great shape. I've read every thread that comes up when I search for 250 on here, and I swear not one thread says the same thing. Some people say the engine is longer, and that the firewall has to be cut or the radiator moved. Other posts said they didn't have to cut the firewall or move the radiator. If you have a 250 in a AD, please post. I'd be interested to see how it worked out.
Is it as easy as bolting in a V8 crossmember? Langdon has a 250 mount kit, but I haven't heard back from them yet.