Hello all. I am a new comer here in search for some assistance. I have a 67 Nova SS with a 355ci, fenderwell Hooker headers, Holley 650 double pumper, Edelbrock Performer intake, Fuelie 2.02 heads, TRW flat tops and a Vertex Magneto. The car is kept mostly in storage, sometimes for months at a time, and has seemed to develop a new problem. I noticed that the engine was running a little rough and figured that it was misfiring from a set of fouled plugs or something. So I changed the plugs, although they looked fine. Needless to say the problem still exists. I figured that maybe it might be the carb. The carb is old and beat and needs replacing regardless, but I haven't had the chance to do that yet. The more I drive it the more I think that maybe it's not the carb but the Vertex Magneto that’s causing the trouble. The car appears to be misfiring at all times and even produces some small backfiring with normal driving behavior. It's at its worst around 2500-3000 RPM where it shakes the car vigorously and almost seems to fall on its face. My tach is also going synchronously insane at this point. Once I am passed 3000 RPM it returns to its "normal" crappiness. After sitting for a day or so I'll take it out and it appears to run better and even seems to improve the more I drive it, but once it sits for a few hours after that, it REALLY runs like crap. Is it possible that something in the Magneto could be causing this or do you think that I have a completely different issue altogether? The car sat for year in a fairly damp warehouse before this problem began. Any thoughts would be appreciated. Thanks.