Surging big block
 

Hope somebody can help me with this problem. I have a 67 Chevelle with BB 396 bored 30 over with a 800 Holley and other things to make it run good. Here is my problem when I take in first then shift to second the car starts surging so bad I have shove the clutch this happened in third and fourth, when I gain some speed it will stop if I slow to 35 mph it surges a little.
When you read this I hope you understand, if not let me know and I will do my best to explain it better. This surging is a real pain in the butt.
Thanks
Mike

I am amazed that nobody replied to this...OH,nevermind..just noticed this was your only posting and you will probably never read this. But just in case someone else has had this issue, I will share my thoughts. It sounds simple, the carb is starving for fuel wether the lines are too small/too much rubber before the pump(collapsing) or the pump is not putting out enough fuel. Crickets resume ......

BBC starving
 

Eric thanks for responding to my post. I don't post to often because it takes a very long time before I get someone to respond. I will look into your suggestions. Someone told me to reject the carb to.
Have a great holiday

The return spring also could have worked itself loose ,mine has done that .

mikes67, sorry your post was missed and you didn't receive any replies. Even if we can't help we try to reply so you know we're not ignoring you.

Is it bogging down? If you give it some gas will it pull out of it and smooth out? Do you know what RPM's the engine is spinning when this happens?

Maybe a leak around the gasket base of the carb? This is not my area of expertise.