Car runs like crap

[Chevyboy_0]

I have a 70 Chevelle with a 350SBC and a HEI ignition in it with a Carter AFB 600 carb on top. as of the past few days she has been missing and running like Sh*t. I hooked her up to the oscilloscope and the coild is punching out 50KV, the wires range from .600-2.9 Mega Ohms resistance, and the plugs are brand new Autolite AR135 gapped to .035. When shes under a load from idle to 1500rpm shes fine anything higher then that dont even think about it, she misses and has no power and the gas mileage s TERRIBLE im at my wits end and dont know what else to check, im just hoping someone can give me another outlook on this. thanks

Andrew

 

[snicklas]

Just a few things I could think of and you may have checked, just thinking out loud....
Fuel Filter
Fuel Pump - What pressure are you running.
Bad cap or rotor..... we had one a SBF that cracked a cap and ran like poo......
All wires in bottom of distributor good...... Dad had one that had a shiner in a wire and would ground out the dist.....
Good fuel, water in fuel, frozen lines?
Fuel Tank vent plugged? Drawing a vacuum on the tank.......
Air Filter plugged?
Is the exhaust system free flowing.... had a cat plug up once and the truck would not run much above and idle......
How does the oil look? Have a 4 banger like that right now, and I have a little milkshake on the dipstick....... that one is going away....

Hate to ask the simple things, but I dont know how many times that I have troubleshot something that had a very simple problem...... I work on alot of Small Engines and it is really frustrating when you have been working on one and it will not fire, and you tried everything several times just to find out the fuel tank petcock was closed, or the tank was empty........

 

[Chevyboy_0]

i figured it out today, the Mechanical advance was seized up in he top of the dist...got it freed up and now she runs like a champ

 

[snicklas]

Cool, something that I did not think of...... Glad you got it running.....