New Carb Edelbrock or Holley?

[68modstang]

Alright, I'm prepared to duck on this one- I'm buying a new carb for my 5.0 crate motor for my 68, nominally rated around 300hp. The car will be a daily driver and I need both reliability and performance. I'm debating between the Holley Street Avenger, the Edelbrock Thunder series and performer series. Running the numbers tells me something around 600cfm. That being said I don't see many differences between the Edelbrock thunder and performer other than cfm and minor adjustments. To add to my confusion a fellow enthusiast tells me that in his experience Holley's are under rated for cfm and edelbrock tend to be over rated. So Holley 570, 670 or edelbrock 600 or 650? The Edlebrock will cost more for the thunder, and less than the Holley if it's a performer. But the big question is reliability and performance?

Thanks.

 

[67coupestang]

personally i never liked my holley because it seems it was always out of tune... My carter/edelbrock is quite simple, and in my opinion very reliable... I hear a lot of people saying if you want all out horsepower get a holley and tune the crap out of it. but edlebrocks are good for the daily driven... Just my 2 hundreths of a buck

 

[D.Hearne]

Holley 600 cfm is all you need. I'm running a used one I picked up at the local speed shop for $125. All I've done to it is swap in a set of 3310 fuel bowls, and a purple secondary spring, set the idle speed and mixture screwsand removed the entire choke mechanism. All this was done 4 months ago, haven't touched it since. That BS about having to tune a Holley constantly, is just that----- BS. BS from someone who didn't know diddly-squat about carbs.

 

[diablopony]

I've run both the Edelbrock 600 Performer and the Holley 670 Street Avenger on my gt40 5.0 crate motor. I had both carbs tuned at a dyno shop with the following results:

o Edelbrock - very easy to tune, idle quality was great, electric choke worked perfect all the time.

o Holley - a pain to tune (there was some drilling needed to get it to idle right), idle quality is OK not great, electric choke works right sporadically, performance was very good. I was able to get 10 - 20 more HP throughout the power band.

I have the Holley on my car now and I have no plans to go back to the Edelbrock. Granted this was the Performer not the Thunder Series, so that might make a difference.

 

[Max Power]

The reason the cfm number are different is because Holley does theirs wet flow and Edelbrock does theirs dry. Wet flow is more accurate, as that is how a carb works in the real world.

I have heard stories about Holleys being so difficult, and I have experienced it on minimal occasions. I have also heard horror stories of Edelbrocks just dumping fuel at WOT on the dyno and going over rich. Both will work decent for the street though.

 

[68 & 00 GT]

I have a Carter 625. Exact same as an Edelbrock as far as I know. What I really like about it is that everything in it can only be one way. Just adjust your a/f and that's it. I can take it apart in 2 seconds to clean it out here and there (car sits off and on). I had Holleys, and they were a pain. Never really could get them to work right. But either ya love Hollys, or you hate them. I'll never own another. For a daily driver I'd go Edelbrock. Not near as many people out there now days that can properly tune a Holley like there used to be. IMO w/ a Holley you just looking for a long term headache unless you can tune it yourself.

 

[rbohm]

i can say, since i have used quite a number of different carbs over the years, that the holley, the edelbrock/carter, the 4100 autolite, and the quadrajet are all good carbs when built right. the 4100(yes you can get a 600cfm autolite just look for the 1.12 carb) is going to be the most reliable and fuel efficient of the bunch, with the qjet coming in a close secondas far as fuel efficiency is concerned. the holley will likely give you the best throttle response, with the edelbrock coming in second. they all have their tuning quirks, the holley needs to be partially disassembles and the fuel bolws drained in order to tune it, the edelbrock only needs the top removed to change jets. the holley has fuel running through a gasketed area where as for the most part the others dont. the qjet and edelbrock carbs are easily tuned by changing metering rods, and you only have to remove a small metal cover to do so. all in all i like the edelbrock, then the holley, then the 4100 autolite, then the qjet. of course if money were no object then i say dump all those and get a set of webbers!

 

[coolblue65]

I have only had experience with my Edelbrock (Performer 750) and so far I am really happy.

I was recently considering trying something different until I had it dyno'd and saw how smooth and flat my fuel mixture was across all RPM's.

Like others have said it is a really easy carb to tune and I have never had any hassles with it since I bolted it on-5 years ago.

Unless your car is strip vehicle go with the Edelbrock.

 

[washMO66]

I had a Holley 670 Street Avenger on my 347 for a while, it seemed fine but I wanted to step up since I do race it several times a year so I went to a mechanical secondary mighty demon, it was a pain to get tuned but once it was in it was great.

I used my 670 Street Avenger for less than 500 miles and I'll sell it to you cheap if your interested. I was just getting ready to put it on eBay anyway. PM me and I'll e-mail you pics. I also have a pro-products polished dual plane intake that needs to go as well.

TB

 

[foghorn67]

Ebrocks are for people that have a carb-phobia.
There is nothing complicated about tuning a holley type carb. I had a Carter, and couldn't wait to get rid of it. Yea it was a slap it on and go...but tuning never came at a fine increment. This is why I think they always give up the edge when it comes to a dyno day.

 

[taylor4g63]

I had a Holley 670 Street Avenger on my 347 for a while, it seemed fine but I wanted to step up since I do race it several times a year so I went to a mechanical secondary mighty demon, it was a pain to get tuned but once it was in it was great.

I used my 670 Street Avenger for less than 500 miles and I'll sell it to you cheap if your interested. I was just getting ready to put it on eBay anyway. PM me and I'll e-mail you pics. I also have a pro-products polished dual plane intake that needs to go as well.

TB

Pm'ed you.

 

[foghorn67]

Pm'ed you.

me 2.

 

[Gummi Bear]

Put me down for being a lazy bum. I hate tuning carbs, I wanna turn the key, and have the sumbitch run. That being said, I've experimented with some different carbs, Holley is my least favorite (and least suited for my driving 'style' ) So I have an Edelbrock 600 cfm, and it did serve me well, in a moment of desperation, I bought a Carter 625 (rebuild kit would take a week, carter on shelf, had to get to work the next morning) It was an expensive thing to do, but I couldn't afford to miss work. Now, I'm removing all that is 4 barell on my truck, and will soon have for sale both carbs and an Edelbrock Performer 289 intake (makes best torque between 0-5000 RPM) all for cheap. Both carbs could use a rebuild (they are dirty, and need cleaning/rebuild) I'm going back to the Autolite 2100, until I get the rest of my stuff together for the SEFI swap . PM or email me for details on super cheap fuel delivery.

 

[mustangdave]

As far as tuning goes, the Street Avenger appears to be really easy; an external spring change, visible float bowls, etc...