no spark

I've been running one of the cheap eBay "A Team" HEI distributors on my 250-powered lemons racer for like 8 races now. Trying to get my new motor firing and I've got no spark. In total I've tried 3 different units: the "Old" one, the "backup/spare", and a brand #$^*ing new one out of the box...

Well I overcame the misfire from the bad gas and about 3 weeks later another one popped up, but this time it was something else. Ignition, it would be fine at some times and horrible at others. Eventually it became if I layed on the throttle more than halfway it would spit and then die then if I...