I have a 383, with an edelbrock 750 on top,

I just did a quick rebuild on it, replaced gaskets and such,

The car runs fine at half throttle, and even full throttle for a little bit, but then when i reach about 3800 RPM the motor bogs, the nose drops, and it feels like it's going to stall out unless i throw it in neutral and feather the gas. It wont always do it with just the primaries open, but if i open up the secondaries then it almost always does it as soon as i step my foot down. after it bogs down it still feels like the motor is struggling and i have to rev up the engine in order for it to stop doing it and drive normal again...

What is probably causing this?

I'm running a mechanical fuel pump, no regulator, but it's a performance holley pump, and is pretty new...

Help Please!
Thanks.

 

You have a carb pickup in the tank? Is this a car that had the in-tank pump and a mechanical pump? Not trying to suck fuel through a dead in-tank pump are you?

 

All i have is a mechanical fuel pump.

 

1st you need to find out if it is rich or lean! use a wide band and find out if your sucking the bowls dry or if it is dumping to much fuel in at that rpm.

 

Not much to go on...

What size fuel line are you running?

What is your fuel pressure?

Float setting, jets and power valve size?

What is your timing, initial and total?