Hi all, My friends 1978 crrewcab(400 with a duraspark) won't start. I tried switching out the "box" I put a different coil on it and it still won't start it has no spark, BUT as you let off the key from start to run position it tries to fire for a second....any ideas or trouble shooting suggestions, I am up here in the woods of Maine and my books are in Pennsylvania. Thanks
Possible ignition switch???
Distributor pick up is magnetized with the key in the on position.

 

Make sure you double check all the wiring. Make sure your missing or have some loose ground wires. Ive heard bad things about that box. id try switching to an msd.

 

Make sure your NOT* missing or have any loose grounds

 

Could be a faulty ignition switch considering what you said about the switching behavior.

 

Sounds like a faulty ignition switch or a fused out ballast.