When I got my '68 it had a Holley 750 on it. It was not running well, and with my long and hateful relationships with these carbs from hell, I decided not to tear into it, and simply got a new Edelbrock 750. I did the same thing with the 350 in my Monte Carlo, and the Monte runs much better, with better MPGs too. So I get it all connected, and everything is great-right out of the box I didn't have to change a thing. This was ok for about two weeks. Just recently, I have begun having a lean stumble problem with it. When you go to accelerate just a little (like in normal town cruising) it will stumble and bog and sometimes die altogether. Now, I do not have the choke connected yet, so I have it adjusted full lean so it is wide open all the time. This causes problems when the engine is cold, but I know why that's happening. What I don't know is why is it doing this when warmed up? I filed my primary metering rods down a little on the cruise stage so let more fuel in, but it made no difference. The next step rich is only a .002" difference, and I KNOW I took more than that off the rod, but why is it not affecting it at all?!? This is on a solid-lifter 454 with a mild cam and automatic trans.

The fuel for your idle circuits doesn't depend on the metering rod size or position. There are idle fuel pickup tubes that have a restriction in the bottom end which determines the amount of fuel available to the idle and transfer circuits.
Provided everything is working OK with your accelerator pump system, you may need to go a little larger on the idle fuel restrictions. 002" at a time is the best way to sneak up on it and not end up with restrictions that are too big.
If you can't find relevant info on Edelbrock's web site, their tech line guys should be able to help you out.

Good luck,

Louie

Hey, Can I have your old 'junk' Holleys??

As Louie said, the rods have nothing to do with the idle circuit, so it won't matter what you do to them, it won't make a difference. Basically, what you are running on at the point you are talking about is the idle and transition circuits. IMO, the transition circuit is one of the weaknesses in the Edelbrock carbs as they are not easy to adjust. Have you played around with adjusting the pump shot lever? Sometimes that can help, but you will probably still have some hesition or bog. I messed around with mine for over 2 years and still could not get rid of it! That's why I'm all Holley now! If you decide to take on the project of modifying the fuel pickup tunes, listen to Louie!! He really knows his stuff about those and has helped me fix my carbs after I screwed them up modifying like that!

Anyway, best of luck,
Bill C.

I wish that there was a carb with the tunability of a Holley, but that didn't leak and run rich all the time like mine do. I finally bit the bullet and put my holley back on. I played with the accel pump lever on my Edelbrock, but there are only three setting on it, and I can not get it dialed in exactly like I want it. My Holley runs best with the idle screws tight all the way in, which I know means it is leaking gas somewhere but I guess I'll run it until it craps out like all my others. Oh yeah and bye-bye to mileage, I gained 3 MPG with the Edelbrock, but that's probably because it was never feeding the engine enough fuel anyway. Oh well.

I had the same problems with my 80 el camino, 40 over, zero deck, balanced, blueprinted, aluminum head 305, yeah laugh but it runs like a bear, built 700r4, 3:73 posi. Changed carburators, 2 different q-jets built by one of the best carb guys in Illinois, changed to a holley, same stuff, went thru the distributor completely, new MSD coil, pickup coil, manmade ligthning moudule, cap, rotor, wires, and AC plugs. Same thing, changed to NGK racing plug, zoom stumble gone.