Edelbrock models 1405 versus 1406 carburetors

I have revisited this thread since I have made a couple of mods which I would like to share.
In regards to the off idle stumble and the lean surging at low cruising, You can try the following. Before I stepped up the jetting to #23 and #19 according to the manual. This does work but in some cases the off idle stumble and lean light cruise still lingers. I have done the following. The idle jets on the 1406 are small about 36 thou orifice size. I drilled out the idle jets on the primary venturi clusters to about 45 thou. This totally fixed off idle stumble and light cruising. GONE. This allowed me to move back to stock jetting in cruise mode. In power mode I needed more fuel there so I use #2 setting according to the manual which consisted in a .095 jet in the primary with a 070/037 metering rod. If you look at the reference chart for the 1406 this will remain the cruise metering stock and increase the power metering by 4%. No flat spots, no stumble and excellent economy since we have gone back to stock cruise metering. Don't forget the idle circuit can contribute fuel metering at light cruise up to maybe 50mph. As far as the idle adjustment, unfortunately there is very little adjustment because of the larger idle jetting (which was drilled out). On a engine with a performance cam(low vacuum) this will benefit idle smoothness regardless of the lack of adjustment. I only have them out only 1/2 a turn. Idle is smoother than the any Holley I have had. So It does not worry me. The secondaries I have just used the primary jets .98 jets. (just swapped primaries with secondaries jets).
As far as the secondary bog is concerned, I have done a small mod to the secondary vanturi cluster by drilling a second transfer port no more than 1.5mm in diameter on the other side of the venturi which will transfer fuel a bit quicker during transition. Make sure you drill through one side of the tube aswell. This made a difference and the bog is almost non existent (but not comlpetely gone :pale:). Although I have not played with the pump shot yet) . Drilling this second port will not affect the main metering. Its just supports the transition. If it has no effect it wont hurt the carb. I have attached a photo of what I did.
Sorry to revisit this thread but I hope it will give you guys some ideas about this carb model.

Regards
Billy D.
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