Holley 3418 67-68 L88 carb

[1969Camaro]

I just bought a 3418 Holley, 855 VS, 2 corner idle with the spivy’s on the 2 boosters

The rear 5253 metering block has the IFR drilled all the way through to the other side. There is no brass restriction in place. The 2 holes are directly inline with their IFR, almost like they drilled to far. The holes are around .026

At first I thought that Ricky racer went drill happy, but I have found 5 different 5253 secondary blocks with identical holes, I cannot find these holes in any other metering blocks.

Why are they there?

Leave them alone?

Plug them?

[rgalajda]

Can you post a picture?

[rgalajda]

Is there an air bleed in the lower main venturi ? Some of the factory OEM carbs such as list 4346 1969 780 cfm and list 4803 1971 LS6 have these.

[1969Camaro]

If I could figure out how to make the pictures smaller I would send it. The holes are in the idle wells.

Any idea how to shrink down the pictures would be appreciated.

Other than these 2 holes, everything else is normal. The carb does have the angled brass tube in the right side primary that connects to the vacuum pod

[1969Camaro]

https://share.icloud.com/photos/025Gj6O ... H5KU-xq-rA

[rgalajda]

Is this the carb that's on eBay?

[rgalajda]

Did you notice that there is no transfer hole from the main well beside where the IFR would normally be ? ( Idle fuel from main well passage )
The IFR IS the drilled hole from the float bowl side into the idle well.

[1969Camaro]

Not the one on eBay, I got this one locally. The holes you see on float side are the same as the IFR

[1969Camaro]

I see it now!! Any reason why they would have done it that way instead of the normal way ?

I am glad that I removed the plugs that I had put in.

Why on this carb?

[GTO Geoff]

A few performance carbs have the idle cct feed direct from the float bowl, & not via the main well. I assume it gives more accurate main cct metering.
Carbs such Comp Series TQ, Weber DCOE & IDA have this.