jonahdeich

I have a 289 coupe with MSD 6al box, blaster 3 coil, pro billet distributor, custom intake air cleaner, and I am in desperate need of a new carb. What's better Holley or edelbrock? Which model an manifold

67mustang302

Intake depends on the rest of the engine. Holley is better for performance (or Holley type other brands), Edelbrocks are much simpler to deal with.

Gun Jam

The Holley Street Avenger 670 with vac secondaries is a pretty good carb. I liked it much better than the edelbrock with mech 2nds.

I run a QFT HR 600 now with mech 2nds it is built off the holley and is almost identical to the holley SA 600 but has some really cool features like removable air bleeds and even better removable power valve channel restrictors and down leg boosters.

I actually like both the SA and the QFT quite a bit.

-Gun

67mustang302

Did you get your QFT totally dialed in?

clowe1965

Edlebrock is set it and forget it, holley's you may have to fiddle with every few months with the weather.

Need some more details for your engine (cam, heads, use). What's wrong with your current carb?

Gun Jam

Its not too bad actually. It might be a bit rich at part throttle cruise it could probably stand a slightly larger high speed air bleed. Makes good power a few little oddities here and there that Ill look into more later I would say im 85 to 90% happy with it

The one thing the QFT does that the Holley does not is it runs quite rich off the line on easy normal street accel...you'll start to let the clutch out and it will lean momentarily to around 15 AFR then crash dive to around 10.5 and run there for a good duration of 1st and sometimes even second. I am trying to figure out if its still a Power valve issue or not....Maybe I'll look into this again soon

Other than that one little thing its pretty much all sunshine and bunnies as far as I can tell.

I also got side tracked with timing and distributors and ran into issues with a machine shop and them pressing on a new steel gear....

Al Newman

Carb advice via this or any other forum is so full of bad or misinformation, it would be foolhardy to attempt to follow any of it. Most folks run carbs way to big for their motor's needs. Bigger ain't better by a long shot. Throttle response is compromised, economy is hurt, and engine life can drop significantly. Whether you run a Holley or one of the derivitives, or an Edelbrock or one of it's clones, is much the same as whether you are a Gm or Ford guy. Nobody else's opinion is gonna change yours. You probably can't miss with a really well remanufactured Autolite 4100 (108 series). My personal preference is a Carter(Edelbrock) 500 CFM for street use and a Holley 4150 series with center pivot floats for road racing, but, my preference is not going to change anyone's thinking.
Good Luck
Al

67mustang302

The Autolite 4100's were really good carbs.

The newer Holley archetypes work well since many of them have upgraded booster designs that produce way better signal. You can run a larger carb today than in the past and still have good signal, but there is a limit. The bigger the carb gets the bigger the reduction in signal and the worse it operates. Smaller carbs are easier to tune and tend to work a lot better than people think.

I think it's the NASCAR Busch engines that are running 390cfm carbs....and they're still putting out over 600hp from 348cid at 6,500rpm.

jonahdeich

Thanks for all the info, I think I'm going to do a build thread today to tommorow with the pictures I have!

jonahdeich

I went with the Edelbrock intake manifold #7212 and the Edelbrock carburetor #1405