Dual quads versus big hammer!!!...

yellow rose said

The chart helps. You need to get a vacuum gauge on there and look and see what you have for cruise vacuum. Set your springs based on that.

I had to pull out my old Carter carb book and refresh my memory. If the stiffest (quickest opening) spring you can get opens at 8 inches, you may have to use some thin washers and shim it up a bit. I'm thinking you'll be 16-18 inches of cruise vacuum...maybe a bit less because I just remembered you took some gear out...so if you can be at 10 inches or so when the spring pulls the metering rods out of the jet, you will most likely clean up the lean spot.

Back to reading. I had forgotten a bunch about these carbs. Makes me want to correctly modify a Strip Dominator and do a TQ for my junk.

Click to expand...

Everything I'm reading says the vacuum keeps the rods down at idle. And generally speaking their thinking you have the same vacuum at a steady cruise at low RPM. When I check my charge for my Edelbrock so I use the yellow spring. But again remember they had bigger primary so they weren't trying to suck it from such a small hole like these smaller Street demon primaries. So I feel I'm getting more vacuum with these carburetors.I've been trying to jet down enough to not have to turn the idle mixture screws in past 1 and 1/2 turns but again like my Edelbrocks in near 3/4 of the turn to 1 and 1/4 turn. And I'm at about 1 turn to 1 and 1/4 on all of my idle screws. the first thing I'm going to do is get it warmed up and take it for a short drive tomorrow and then just start putting fatter or stronger Springs in and see what happens now that I seem to have this idle and everything else under control. Also I do have those 31 squirters up top and I can put stronger squirters in as well to see if that helps again.
One more thing I have is those metering rods coming the 58/44 s and 58/50 s...
Again that article States putting richer rods in the front carburetor...