I guess my ignition switch went out, when its on crank it starts and when I let the key go it kills. Its on a 1966 Satillite where would I get a new one?

Sounds like a ballast resister, have to tried that first ?

You can verify two things by using a volt ohm meter on the ballast resitor, one is the resitor and the other is the ignition switch and wiring by having someone else put the tranny in any gear other than nuetral or park and turn the key to the start position while you put the volt meter leads on both ends of the ballast resitor to see if you have voltage or not. You should see voltage on one end but not both If you have that then have the other person release the ignition switch to the run position and see if you have voltage on both ends of the resitor, you shuold have 12+ volts on one end and less volts on the othor end going to the coil + side in the run position
Let us konw what you find please, that may help others on here later

Yep, start with the cheaper and easier fix. And if you have a multimeter you can check it first.

Bad connection at either bulkhead or ignition switch to under dash wiring harness.

it had a MSD-6al with a accel super coil no points. When I took the resistor off it had rust on the ground, that just may have been the ground wire someone put under the resistor.

Well when I cleaned the rust off and put the resistor back on it cranked right up, good thing I didn't go buy a new switch it looked like it would be hard to change with my big hand. Thanks a lot fellas.

the ballast ain't grounded so it sounds like you just had a loose connection, one of the ones that you were dealing with in working on this issue. All good now & if it acts up again just check your connections in the blue wire (ign1 "run") circuit

Corrosion is a good insulator and causes many problems with electrical cicuits in cars and every thing else using electricity including airplanes
It pays to trouble shoot the problem first before replacing parts