Need your input on what you think....

Ok so I got my pulling truck running weds. night and took it to my first pull for the year(couldn't sit the whole season out). Last winter I ran a leak down on it and the best cylinder was 38% and the worst being 100% back through an intake valve. When this happened I just figured it was the valve and put it on the trailer and brought it home. After watching the video some more I'm thinking it may be an ignition issue, last pull last year it wouldn't start and I had to put a new pickup in the dist. I haven't pulled it since. While I was checking things out last year I had the white wire loose off the msd6al box and forgot to tie it back up, it may be grounding out while bouncing around and that's what got me to thinking about ign. instead of valve. While I know the motor is old and wore out and in need of a major rebuild, what do you guys think is going on. The vid is kinda small it was taken with my Iphone by my daughter.

Engine sounds really good. Sounds like it could be ignition.