Hello, I recently put a new comp cam xe274 in my chevy 305 with a holly intake, headers dual exhaust and edelbrock 1406 600cfm carb. The car is a 87 monte carlo ss and when I got this thing running today I noticed that when going wide open or punching on the throttle it has a bogg to it. The motor doesn't feel slow it just feels like the carb has a flat lean bog. I tried richening up the power mode which helped and also installed stiffer 7" step up springs. I also noticed that the car breaks up a lot if you install the accelerator pump linkage in the top lean spot and sounds much smoother if you move it to the bottom hole or rich spot. I feel like my carb wants more fuel but my power mode is already in its richest mode.




Sorry for the long story but does anyone have suggestions or do I need a different carb.

 

The 1406 comes box stock leaned out.

Move the pump linkage to bottom richest hole.
Put a vac gauge on engine, tune the idle air mixture screws to get the highest vac reading you can.

Now divide that reading in half and install step up springs that are the closest to that.

Put #1455 073 x 042 metering rods in and you will be good to go.

 

having same problem, isn't the richest hole the top hole closest to carb?