Does adding a dual feed line (#8133) help the performance of the 1806 AVS carb. Hate to waste the $$ if there isn't any positive results.
Thanks for any feedback.

I did it on my AFB when I put the turbos on it in 2001.
Is it useful? Maybe.
If you've got a traditional hot rod or even a low 11 second street car then you're probably wasting your time.
Look at the size of the needles and seats. Is your engine going to be drawing the fuel faster than a 3/8" line at 5 psi can flow?
Probably not.

The crossover tube in the back of the air horn assembly is about 3/16" diameter. That has to flow enough to support a 1/10" needle and seat on the far side of the carb. 99% of the time that is a non-issue.

If you're slinging high G maneuvers like sustained cornering on road courses or autocrossing that might inhibit fuel flow through that tube then you should look at the dual feed.

Is that an Eddy AVS or an OE AVS? If there's enough demand that Holley offered a dual feed I'd think you could possibly starve an Eddy also tho I'm presuming a racing app and one of the Eddy AVS's that are larger CFM. The OE's are pretty small so would pass less fuel so might not hit the wall w one of them. It is a nice touch to drill/tap a dual feed & as as you know larger needle/seats are avail

I put one on my edelbrock performer carb,i drilled/tapped the other side for the duel feed line to hook up.

cant tell any differance in it,worked just the same as it did with the single line.

for a long time I thought i was the only fool that bought one for 75$ when they first came out.never have seen anyone else with one but have read at least 2 other members have used it.

now its on my 440 engine,i took a tubeing bender and bent a 180* U in the lower feed line so it now has the feed from the rear of intake.

what sux is you have to buy a eddy filter by itself or another single line with filter...which was cheaper to buy the single line and filter than just the filter..go figure

I have had it for a long time now(10 yrs) and just opend the filter to clean it. found some bigger chunks of rust and its rather clean inside for the long service it has had.

so IMHO...its not needed but looks kool

when i had the 750 eddy and went to the 600 eddy,i lost some top end but gained drivabilty at lower engine speeds. sounds like you need more carb for top end.

IMO eddys are a great street carb,set it,forget it but a holley gas hole will out do it for performance hands down.

With the plugs showing white & your heat range correct & timing good yes I'd go richer on the rods and or the jets and a i.e. .003" jet change is far more than a .003" rod change as enlarging a doughnut gives you more area than reducing the center hole so to speak & you may very likely need a larger carb but I'd experiment w it first jetting/larger needle & seats/float level/secondaries before the dual line and dial in your timing before the carb. I'm thinking this carb should be pretty rich as is tho modern no lead gas does not show the color of yesteryear. A person really needs a LM-1 or 2 A/F meter & I'm in the same position just guessing w my eddy 600 1406. There are some very good in depth plug charts avail, check the archives and or google it