66 Dart lost keyes

The easy and cheapest way is to replace both the cylinder and ignition switch.
You either need a key or able to pick the cylinder to get it out of the switch.
Regardless, you'll have to remove the switch.
I can sell you a new switch and cylinder w/keys for $30 and the ride.
The biggest issue is that the door locks won't work and you don't have a key for your trunk.
You can get a locksmith that can make keys.
I can square you away for less than a locksmith, PM me for more info.