Currently have a Holley 3310 vac secondaries on my .30 over 383, electronic ignition, M1, 10-1 compression, balanced lower end, stock 906 heads, and 383 magnum cam with stock exhaust manifolds, 727, and 3:23 rear.

Thinking about a Holley Avenger 770. Do I need the aluminum version? Anyone have any opinion on this carb? Other recommendations please. Thanks.

Hope everyone is safe and well!

Stay with the 3310 and tune it.

The best out of the box carb today is the new Street Demon. Hands down. It has features that older carbs do not. Compare them feature for feature. And the tune is good, too. They are available in 625 and 750 ratings.

https://www.youtube.com/watch?v=TRpmtLb_9dI

The old 3310s are good carbs, but need several changes to be right on our Mopars. The 2 biggest problems with them are that they are way fat on the cruise requiring main jet and PVCR changes. And the secondary opening spring will need changed. As long as you are good with tuning, they can be brought around.

Dave, any idea if the Street Demon will clear my factory air cleaner for my 71 Challenger?

They keep saying it's an all new, clean sheet design but it really looks like a modern day thermoquad without the metering rods. I guess these guys have never seen a thermoquad.

There are better places to spend money.

Actually, if you read the history of the Street Demon, it was designed by former Carter engineers. So, it's basic design similarities with the ThermoQuads is no accident. But, there are profound differences between the ThermoQuad and the Street Demon. The uninitiated may call it an updated version of the Thermoquad. But it really is a total redesign of the old Thermoquad.

So how about this; other than the basic outward appearance, why don't you list the common points between the 2 carbs?

Well then since you are obviously so initiated how about you list what the differences are instead.

Unless there’s something wrong with the 3310, Me thinks that on that on that pretty close to stock combo, you’d get more return per $$ by swapping out the M1 for a Performer RPM than you will a carburetor swap.

The gEeZeR GEEtar in a round about way recommending a Plastic Fantastic??!!

The smog free air of West Virginny must have UNCLOGGED his thinking process

That’s soitenly NOT a Looney decision...

there's no practical difference between the 3310 and the 770. throttle bores and venturi are the same so there's nothing to be gained.

The Quickfuel Slayer series looks like the good carb for you. Very tunable and gets very good reviews
https://www.summitracing.com/parts/qft-sl-750-vs/reviews

Gus

"Well then since you are obviously so initiated how about you list what the differences are instead."



I am obviously much more initiated that you on these two carbs. In fact, it is apparent that you knew very little or nothing about the subject when you commented on it.

I can, in fact list many differences between the Thermoquads and the Street Demons. And have installed, or rebuilt both many times along with installing and tuning many 3310s. That experience is how I arrived at my opinion. Have you ever even had your hands on a Street Demon?

How about this? I'll match each and every design point that is unique to both carbs that you know about with a design difference that the Street Demon has from the Thermoquad. And that is with the benefit of you having time to do some research. Which you will clearly need to do since it is obvious that you are ignorant of the subject that you commented on.

Good luck.

The key question for the OP is whether he wants to tune a carb or would rather bolt one on and go?

One of the most important reasons I have for recommending the Street Demon carbs over other carbs is that their tune is closer to what a mild street driven Mopar wants than any of their competitors that I have tried. They have some other useful features that are unique to them, but their tune is the key ingredient. Nothing is perfect, but I have not had any problems with bolt on and go with the Street Demons.

The problem with the Holleys is that every single one I have ever bolted on has been FAT! Often way fat, particularly on the cruise and low speed transitions. And those are the areas where street cars spend the majority of their time. They often drive okay because our engines are much more tolerant of an overly rich running condition than they are of a lean one. Can they be tuned out of that? Absolutely they can. And it is not that difficult for someone with some understanding of Holley's circuits and has easy access to some parts and tuning tools.

'Easy to tune' is not the most important thing for most guys looking for a carb for their mild street car. 'Little to no tuning required' is usually what they are looking for.

The Holley Avenger carbs I have used, seem to be setup for emissions / economy.
I have the 670 cfm Truck avenger, and the 770 Ultra Street Avenger.
On both, I had to enlarge the idle feed restrictions.
The power valve restrictions might be OK depending on your setup. I think both of mine are a bit bigger.

For the cost of the Ultra Street Avenger, you would expect the metering block to have screw-in restrictors, but it does not.

I have a combo very similar to the OP's.
I put a 650CFM AVS2 on it, leaned out the metering rods 2 steps on the primary side, and it runs great.
It's just a street car, though.

I'm not sure why you insist on being such an ass. What did I say about the Demon? Here's some help for you, "it really looks like a modern day thermoquad without the metering rods." And it does. You have offered nothing to dispute that except to attack me. So instead of derailing the OP's thread I'll just put you on ignore and you can continue your pissing match by yourself. Have a great day!

back in the day I had a 383 4spd road runner. I tried different carbs with the stock intake (factory stock engine and exhaust); stock avs, 440avs, 780 holley, etc, and I can't say that any of those carbs that were larger than stock made much difference. i'd do the 650avs2 (nearly identical to a stock avs without the emissions hassle) on the stock intake and be done with it.

OP doesn’t specify which M1.

If it’s the single plane...... that really should go away.

I don’t love VS Holleys, so a new Street Avenger would not be on my preferred list.

Never used the Street Demons, so I can’t really comment on those.

I guess I’m on board with the 650AVS2, on a dual plane intake manifold.

How could a carb be perfect OOTB unless you tune it and find the original tune was best??