Is my carb too big for my 383?

[ted]

mopar didn't make it with a double pumper

[1 Wild R/T]

Exactly
 the springs could be too strong , if you remove the covers while idling the rods should be down if not you need lighter springs

This..... However pulling the metering rod covers with the engine running is scary, those tiny screws so close to the venturi's is a recipe for disaster.....    Before you start the engine you can pull the covers & swap them side to side so only a small part of the metering rod pistons are covered, enough to hold the pistons in their bores but it also leaves the metering rods exposed so you can watch them work..

[Chryco Psycho]

I just back out the screws a little & swing the covers out of the way so you can see what is going on without removing the screws

[Bluemonster71RT]

Your metering rod springs may be to strong for this engine with the lower idle vacuum. If the metering rods aren't seated, you won't be able to adjust the carb with the mixture screws. You might want to get a Holley carb for this engine so you can tune it correctly.

I finally got to check the vacuum while adjusting the screws. The low was 5 and the highest i could achieve was 6. According to the manual for the carb that would mean that I need looser springs.  I also have a dead spot when cruising at about 2300 and give it the smallest amount of more throttle it skips. I have not yet done anything full throttle or over 4000 rpms yet so I don't know what wot is like.

I adjusted my timing to 20*(it liked 24* but was hard starting and thats too much advance I think) initial and put the 18* advance stop bushing in changed one spring to be all in @ 3000. Idle is a tad lumpy at 900.    I have not driven it at this yet.   

[Chryco Psycho]

you want to use 3" rated springs under the metering rods , I would also restrict the idle bleeds but with that carb you can't unless you feed a small wire into the bleed & leave it there

[734406pk]

You may want to consider a Holley carb (or Quick Fuel, etc) with adjustable air bleeds, accelerator pump cams and all. I think your engine build is too radical for the Eddy AFB to accommodate. The tuning parts are limited, so it may not be possible to give satisfactory performance.

[Chryco Psycho]

 

[Bluemonster71RT]

I can trade back for my Holley 670 or TRY to salvage my old old 750 4150 that was originally on the car but it has been molested by a few mechanics because it would never run right on the car. Maybe now it would 

[Bluemonster71RT]

I just got back from a quick test ride because of the new distributor settings. Though it did run better and allow higher rpms, the engine was now surging/stumbling at low throttle cruse and choked a bit on heavy throttle a few times.  My friend has the edelbrock kit with the springs and rods. We'll try that tomorrow before I swap to the Holley. Only because I just need to know.

[734406pk]

I can trade back for my Holley 670 or TRY to salvage my old old 750 4150 that was originally on the car but it has been molested by a few mechanics because it would never run right on the car. Maybe now it would 

Any stripped threads on the 750? Is it rebuild-able and have threaded air bleeds? I hope it's not too molested, that would be a shame. Out of the two, I think that 750 CFM will work best for you.

[Bluemonster71RT]

Ok, I changed the rods to the next step richer and still have the same issue of a stumble with quick off idle acceleration. So I added one step heavier springs =same. I suppose my next step is to make sure that I didn't mis-adjust the floats when I reassembled the carb. If that doesnt fix it I guess I will change the jets. Meanwhile I will start rebuilding the 4160. I found out it's not a 4150 which would or could make it the original carb. The 4160 never had a stumble but was not even half as snappy on the throttle as the Street Avenger 670 I replaced it with. It was a slow steady build up.  I also messed with the timing again as for some reason the car was hard cranking tonight. So its at 18 initial now with the 18* bushing. When running it loved 24-26, just wont start there now.     

[Bluemonster71RT]

Today I was going to check the floats. Before I did that I was reading some things and wanted to make sure the pump spray was good. At best it was spritzing then nothing. It was decent yesterday and when I pulled the top off the carb I noticed that the pump diaphragm/o-ring thing wasn't there on it's holder. I put it back on bla bla bla and when I checked the spray it was good for 3 pumps, then nothing. That sucker fell off again! Fortunately I still had the old one, which was a bit stiffer and defiantly fit way more snug on the holder. Bla Bla Bla, I checked the spray and wow now thats a spray. No stumble of idle but still have to test drive it tomorrow. I wonder if that diaphragm/o-ring thing was the problem the whole time. Maybe I now made it too rich?     

[Bluemonster71RT]

I took it for a romp and for the most part its much better but I have a few pops under hard acceleration and chugs at cruise. Any suggestions? Lean? timing issue still? lifer preload too much?

[Chryco Psycho]

Hard to be sure but lean will cause misfire
 over-advance can also cause misfire

[CUDA8U]

 use the eddy carb as a boat anchor,grab a holley, quick fuel,some jets and a vac guage.I pulled a 750 eddy pile off my old 440,pu on a holley 850,tweaked it.It was atleast a 50hp gain I swear.Them 2 carbs are easy to tune and have many jets with 4 corner adjuster screws.