dropping cylinders 1 & 3

[Seann]

Hi Folks,
Just finishing a custom '73, has same problem as my old '76 Wing....doesn't always want to fire plug unless plug cap is pulled slightly "off", making the spark jump a little farther. Can someone provide the description of what's happening here, and would widening the plug gap solve the problem? Both coils are new.
Thanks,
Seann

 

[amc49]

Weak spark or fouled plug. Widening gap may help if coils can take it. Set yourself up to yank a plug instantly when it does it and see if it's wet. If so fuel issue or something wrong with engine. Low compression can do that. Improper point dwell can do it too, no coil saturation time lowers spark intensity.