edlebrock 600 on 390

[390owner]

Any one else using a edlebrock 600 on their 390. Mine seems to be running too rich,but if I lean it down one jet size it runs too lean and surges. I have a hei dist. and have set the plug gaps to .45. My tail pipe is black and it smells rich. Any ideas

[GerryP]

You're still too lean.  That "rich" smell is hydrocarbons from incomplete combustion.  An authentic rich mixture is carbon monoxide, which doesn't have that eye-watering stink.  If you are super rich, like the choke is stuck full on, then you can get that stinky exhaust.  What's happening is that the mixture is too lean to burn completely and it gets exhausted.  Many times you can also address a lean mixture by advancing the timing to allow more time for the mixture to burn.  But it's better to just richen it up.

[390owner]

So black smoke when reved is from being too lean? Ok I will try to richen it up. I have my timing set as high as I can without being hard to start. I think the total is around 34

[390owner]

Also my new plugs look like this. I am running 89 octane gas tooIMG_3699 by Daniel Crymes, on Flickr

[allrightmike]

Maybe check fuel pressure and float level.

[MeanGene]

Get a 600 Holley and a Duraspark, ditch the AFB and UGLY and crude HEI

[blykins]

It's rich.  It needs to be leaned out in one way or the other.  Following the other guys, check your fuel pressure.

I ran into this with a Quick Fuel Slayer 600 on a 390.   I just think that a 600 is too small of a carb for a 390.   I don't even use a 600 on a 289. 

[Lowrider]

X2 with MeanGene

[fryedaddy]

try some better fuel too.

[e philpott]

What jet and metering rod do you have in there ? Are you sure it's not flooding over ?

 Not my pick for max performance but the Ebock 600 tuned is a good carb , I've put around 10 on late 78-9 F250's out here back in the 90's with 351M400 and performer intake for some farm trucks and it's a whole new truck when your done

[TJ]

When I was using a 600 Edelbrock carb, I used to have to adjust the floats every couple years.  They’d relax overtime and let the carb flood itself.

[Heo]

My experiance with them is they are sensitive to high fuelpressure

[FrozenMerc]

x3 with MeanGene

Let the Chebbie guys play with their ugly Quadrajets and HEI's.

I ran a 600 Holley and DuraSpark II on my 390 powered '75 F-250 for years with great success.  It was not happy out of the box, and required quite a bit of adjustment to get it set up correctly, but once it was dialed in, she ran like a champ.  A wide band O2 sensor made dialing it in much easier then guessing and reading plugs.

[475fetoploader]

I ran a Holley 3310 on my 390 in a 4x4.  Very mild flat top motor.  That carb worked excellent towing, off-roading and driving to work. I’ve never been a fan of afbs.  I ran an MSD billet distributor,  with a 6a box. Also worked great.

[Diogenes]

I have to agree with Brent, 600 is too small for a 390.

There are features of the AFB design that is advantageous when compared to the Holley. I've ran them with success, but I think the Holley is overall better for performance tunability.