Edelbrock 1406 carb

[77ChevySharkBite]

Okay fellas I need some help with my carb, over the past couple of months I've been trying to get timing and other things buttoned up and have the truck running smooth, a recent issue I've had with my carb is that is sputters/struggles when you rev it up but when you drive it, it becomes a little harder to drive.

I let it warm up just drove it around the neighborhood. When I try to put any sort of load on the truck it's like it sputters and struggle and you can audible hear it. It will run and you can give it gas but it doesn't run like it should I can tell that. It idles smooth and fine without a beat only when it's revved or driving and trying to give it gas it sputters/struggles and when driving and you try to floor it, it bogs and what I'm lead to believe it backfires. So does anyone have suggestions?

It's a 77 Chevy with a 350 with headers, mufflers, and intake/carb swap done too.

[INSIDIOUS '86]

Is it a new or used carb? Do you have a tune kit for it?

[78maliburat]

Check for vac leaks then accelerator pump...is it new / used /

[77ChevySharkBite]

Originally Posted by INSIDIOUS '86

Is it a new or used carb? Do you have a tune kit for it?

I don't have a tune kit for it.

Originally Posted by 78maliburat

Check for vac leaks then accelerator pump...is it new / used /

It's a brand new carb.

I'm in Texas so I don't have to worry about emissions, but if it wasn't plugged up to the correct port could that cause the issue maybe?

[77ChevySharkBite]

So I switched which port I was using for my vaccum and wow I didn't know it would make that much difference but now the truck doesn't struggle at all there's still a little sputter so I think I might advance it a tad more but it's nothing what it was, so apparently it was a really simple fix.

[bluex]

Did you dial in the carb with a vacuum gauge using the method described in the manual?

[77ChevySharkBite]

Yes I did as instructed by the manual and DVD that came with it I found out that my issue wasn't timing or carb it was my vacuum hose was connected to the wrong port, so I switched the port the hose was on and boom now it runs flawlessly

[geezer#99]

Originally Posted by 77ChevySharkBite

I found out that my issue wasn't timing or carb

It was your timing! By switching to full time vacuum your motor told you it needs more timing.