Ignition problem... someone please please please help me!!!

[xtreme80]

Here's the scoop. 1980 C10 w/ a 350 crate with about 1400 miles. New tranny. New Edelbrock carb.

During heavy driving where I reach higher speeds, it seems as if my ignition is cutting out. It will run fine till it peaks in first gear, and right before the shift, it starts this hesitation which feels as if Im letting off then accelerating, then letting off, over and over again. Soon as it shifts into second it completely bogs down and feels like a 4 cylinder. It sputters and chokes till I let my foot off the gas. If I keep my foot in it, it'll kill the engine. Even when I let off the gas, it still takes about 5 seconds before it runs normal again. I'm nearly 100% positive it's an electrical issue, and some sort of ignition problem.

Here's what I've done so far to diagnose this problem:

New distributor assembly, pickup coil, etc. New HEI coil, new cap, rotor, plugs, wires. Replaced the distributor power wire. None of these seemed to help the slightest bit.

Here's why I know it's not a fuel issue:

Checked the fuel filter and I can blow through it with no problem. It's also brand new. All my fuel lines are brand new. I wired in an inline secondary fuel pump to help with fuel movement through the lines. Lastly, I hooked up a propane bottle through one of my vacuum lines, and drove down the road shooting propane into the engine. If the engine was being starved for fuel, there was enough propane running through it that it would have fixed the problem temporarily.

It's getting worse and worse too, now it's sputtering during everyday driving, when I accelerate, and I'm afraid that in the next few days it's finally gonna stop running...

Someone please help!