Currently on the car is a 600 cfm double pumper holly (came on the car) anyway Im looking at switching to an Edelbrock AVS (adjustable secondaries) now should I stick with a 600cfm or would jumping up to a 650 be to much? Motor stats are: roughly a 79-80 350 block with 64-67 camel(sp?) hump 327 heads motor is slightly built ie bored 30 over mild cam and stock valve train from what I can tell, and a wiend (sp?) intake. any help would be great

 

Stick with the Holley or switch back to a Q-jet

The AVS Carter is the worst of both worlds.

 

Really? whys that? I've always heard good things about the edlebrock and as for the avs I just like the idea of being able to tune the secondaries...as for the reason I want to get rid of the holly well I dont know how to tune it and where i am there is no shop that could tune one or anyone for that matter...and I was told that a holly has to be fine tuned every time the car comes out of storage...I dont think I would like that

 

You need a new circle of friends. While the AVS is slightly better than the original Performer, it's still a demand-based secondary, still based on the old AFB design, and still inferior to what you already have. As stated, if you go with something else, get a q-jet. You can "tune" the q-jet secondaries just as much as you can the AVS.

Holley's don't need to be tuned every time they come out of the garage. That's absolutely silly. Holley's website (www.holley.com - easier to find if spelled correctly) has just about all you need to tune them. It isn't that hard, and once you get it where it should be, the only reason to change it is if you have a drastic change of conditions - such as going from 5800' elevation like where I live to sea level.

Most likely all you'll have to "tune" on you carb are the jets and power valve. There is more you can do, such as accelerator pump nozzles and pump cam, but what they come with is typically pretty close for the typical street engine.

Is there something in particular you're trying to "fix"?

 

My opinion (and its only that) is based on my own personal experience with this carb. It is way over hyped IMO.

When I bought my 87 442 about 5 years ago the previous owner had swapped in a brand new AVS carb... This was good for me... The car ran so bad with that carb the previous owner basically gave the car away to me. He was convinced the motor was blown. It ran TERIBLE with that carb, nothing off of the line, more bogs then power... impossible to start and impossible to idle... that carb was a bad joke... I limped the car to my parents house and spent hours trying to tune it... Nope this is just how it "ran"....It was all I could do to get the car the next 15 miles to my house...

Long story short... I replaced the broken TPS in the stock Q-Jet that was left in the trunk... Bolted it on, swapped back the CCC dizzy and it was like magic! If your not happy with the Holley, find the stock Q-jet, rebuild it and like me, you will be amazed.

BTW I gave the carb away to a neighbor and he spend almost a week trying to get the carb to work... I think he dropped it off for metal recycling

 

Yea it has it's issues...I'm not even sure that fuel is even going into the secondaries which might be the big problem. As for the problem...it only works good if your just drivning around but as soon as you give it more than half throttle you can feel it breaking down so to speak. from the drivers seat I can't see it sptting any black smoke out so I don't think its flooding it self and all the ignition is new (cap,rotor,wires and plugs) if you ease on the throttle it seems to work a little better but once it gets up into the higher rpm it starts breaking down. Got nothing against the holley its just that no one around here can tune one and I have no idea when it comes to carb tunning, dont get me wrong I love working on stuff and do all my own repairs but I have never been anywheres near a carb so Im lost in that department.

 

You can probably learn all you need to know in about half an hour going through the tech info on Holley's website.

If you have a double pumper, it's pretty easy to tell if it has fuel in the secondary bowl. Test #1 is to open up the throttle and watch for a squirt of fuel in the primaries and secondaries (do this without the engine running). If you see fuel, it's at least got some.

Test #2 is to take the sight plug off the side of the fuel bowl and check the float level. Do this with the engine running. You should just get a dribble of fuel out of the bottom of the sight plug hole. Check this for both the primaries and secondaries. If the fuel level is too high or too low, adjust it using the nut on top of the fuel bowl - the slotted screw is the lock for the adjustment, loosen it slightly, then adjust the nut (5/8" wrench).

 

Just before the car went into storage I actually did do the first test you spoke of...and I didn't see any fuel shoot into the secondaries...now ethier I opened the throttle to slow or I just missed it. Unfourtunetly the car is stored in someone's barn with a bunch of other cars so I can't exactly go work on it, so the second test will have to wait. Would I be able to rebuild the carb myself? or should it be left to the pro's if I can find them haha its leaking a little anyways so I figured I would pull it and throw a rebuild kit at it.

 

I was just reading through the holley site and found something interesting that might be afecting some of my problem....it states that there should be at least 3/4 of an inch between the vent tubes for fuel metering. Now I'm pretty sure there isnt that much on mine cause somebody for some reason stuck a cold air intake thing off a chevy truck on there...you know the ones with the little plastic thing that goes over the throttle body and then it has a big crhome tube on it...maybe that might be at least a little bit of the problem..maybe...by the way thanks for the site lots of good reading on there.

 

A Holley is one of the simplest carbs to rebuild. The only tricky part is getting the accelerator pump levers lined up when you put the fuel bowl back on. Other than that, you just need some carb cleaner and compressed air (to blow out the passages after soaking in the carb cleaner - or use a can of spray carb cleaner with the nozzle tube to blow out the passages after soaking).