A few other things that might be a problem, are the plug wires on good and in the correct order, maby someone messed with it? Maby a sticking float in the carb, my 400sbc did that all the time to me.Is the seal good around the mounting surface to the carb?

My original thought was a vacuum leak......You may also have a bad cam. Another car I had with a 350sbc was that way sputtering and couldn't get it over 40mph. I doubt fuel is an issue, I am thinking more on mechanical or electric. Oh yeah and check your exhaust for a potato!!!!!!!!!

 

No, the real problem is the SBC.........

 

dont know what the sbc is but There was a big difference when I disconected the vacume line. Although when I disconected the line going from the advance to the carb at the carb and drove it there was no difference. what does that mean?

 

see post below accidentaly posted twice

 

SBC = Small Block Chevey

so which is it no change or a big difference? and when you dissconected the vacuum line did you block it off so there was no leak?

 

I disconected the line going from the advace to the carb at the carb and blocked it off, which made no change in driving. Then I took the line off going to the advace at the advance and it made a huge difference, car could bearly keep itself running.

 

You created a huge vacuum leak, no wonder. You have to plug the end that is sucking, on the carb you can use a short piece of vacuum line with a golf tee or a bolt in the end. It's easier to just pull the hose from the vacuum advance unit and put the tee or bolt in there.

 

A little more in depth explenation of the problem might be in order. I like to go fast. I like to stomp on the peddle and burn out till I hit 60. My stang did this for me a while back. Now hes sick. I try to step on the gas at idle and the car will cut out on me. If I press it half way it will sputter and accerate very slowly. If I bearly press it it will excelerate without sputtering. Going into the mid and high level rpms I can step on the peddle about half way maybe a little more and it will excelerate with a little sputtering. If I step on the gas It sputters a lot and bearly excelerates. Oh and the when the car sputters it looses power. Thats why I named this post what I did.

 

The line going from the advance to the carb made no difference if I plugged it or not. I disattached it from the carb not the advance. And there was no suction. Does the carb suck it? If so wouldn't it of made a difference when I unplugged it from the carb and just left it unplugged?

 

Have you sprayed carb cleaner around the perimeter of the intake manifold? Sorry if this has been mentioned, I'm too lazy to read the whole thread.

I'll explain:

You may have a vacuum leak around the intake manifold. Spraying the carb cleaner will temporarily seal the leak. With it running, spray it slowly around the base of the carb and the perimeter of the maniford. If you hit a spot where it momentarily speeds up, that's where the leak is. If it's the carb gasket, you're lucky, 4 bolts to remove and replace. If it's the intake manifold, the gasket will need to be replaced, you may want to find a more experienced friend to help.