I have installed a 1970 351C into my 1990 F250. Had to rebuild everything and buy missing parts. I am not getting a lot of fire to the plugs. Someone told me to install a HEI Dissy and that should fix it. I have got an old points dissy in now. am getting good spark at the points but it not seeing good spark at the #1 wire. Can anyone shed any light on my problem?

 

Are the coil and plug wires new? Do you have full voltage on the positive side of the coil? Those are the first things that come to mind.

Personally, I hate points...I screw around with them more than enough on old Ford tractors. The Duraspark II ignition was one of Ford's greatest inventions, IMO. If you're handy with wiring, it's not too hard to convert over to the DS II ignition. A distributor should be fairly easy to find, as Ford used the same Duraspark distributor for the 351C, M, 400, and 460.

Of course, swapping to the Duraspark won't change much if there are problems upstream.

Good luck,
Pat