I got the new Magnum 318 all straightened out in my 78 Fury. It's a stock 95 long block with a mild Summit cam (K6900), dual plane M1, headers, 2.5" duals with h-pipe, 3.55SG. I am up in the air between 2 different carbs. I'm currently running a box stock 1406 Edelbrock on it. I also have a freshly rebuilt Holley 1850 that I can use. My question is, which one offers more tuneability for the average person? I want to tune for mpg with either carb, but the idea of rods being $12 a pair, and jets $10 a pair kinda push me away from the Edelbrock. I have a Mopar Performance Holley jet kit (64-99), and I'm thinking about that little 1850. I tried to search, but all I found was personal preference. The only advantage I see the 1406 having over the 1850 is the use of secondary jets, instead of a metering plate. Anybody have any actual experience tuning both? Which one is better when tuned correctly? I don't have a wideband yet, but is in the cards for a later date. What are the actual pros and cons of each based on PERSONAL experience....not hearsay

There is a jet tuning kit for the 1406 ...

Otherwise let the holley vs carter bleepfest begin ...

Oh and don't forget the thermobog

I actually love Thermoquads, but hate the idea of an adapter plate, which I need to use on the M1. I have quite a few that run great, but figured I'd get some feedback on some squarebore carbs. I was never an Edelbrock fan at all, and the big 3 used enough of the 1850 based carbs in factory applications, I figured they can't be all that bad. The only Holleys I have experience with are double pumpers, nothing small like this for a driver application.

Here's a BTT as I have a DD 318 eddy 1406 and a rebuilt (by me) holley sitting on the shelf

I always recommend an edelbrock for mileage/driveability and Holley for performance.
Both can be made to run well but I think the ebrock will win in the mpg game.
I am a holley guy but your combo begs for a spreadbore.Not owrth an adaptor but it would shine here.Even a quadrajet would be good.

From personal experiece, The Holley is a sweet carb, and can be tuned to anything pretty easily. i have used many of them.
It does however need some retuning, fiddling, and general upkeep. They are extremly sensitive to small dirt/ rust particles, and the 10percent fuel alcohol mixture we have to use is is not real friendly to the gaskets and accelator pump diaphram is a problem.
The Edelbrock is a good choice for a reliable driver, put it on, and drive it forever with no attention at all. excellent fuel mileage.
Put one on my 68 Charger in 1991, still there, never had to mess with it after inital tune.