Replacement carburetor for 1970 Cuda

[missioncritical]

Hi, this is my first post.

I just brought home a 70 Cuda.  It runs really bad from sitting around for decades, so I have a lot of work to get it road worthy.  The guy I purchased it from was having a local shop do some work on it and they think the carb is in need of replacement or rebuilding.  A couple of decades ago, the prior owner remembered having the carburetor rebuilt, and he thinks he got back a different model.  The casting on the air horn reads 4749-3; its a Holley.  I assume that the car originally came with a Holley.  The motor is a 383 Super Commando with A/C, PS & PB, and automatic trans. 

Assuming this is not the original carb, and I just want to purchase a new carburetor, should I go with another Holley and if so, what model ?  Or is there another brand that is 'better'.  My plans are to make this a driver, as everything on the car is fairly original now.  I hope that after I get the distributor, wires, plugs, etc. replaced that it will run a lot better, meaning I would like to keep the 383. 

Any pointers ?

Thanks

-Kevin

[MEK-Dangerfield]

Kevin,

  Welcome aboard here.   

Holley makes a nice Street Avenger series carb now. The 770 would suit you if you plan to keep this engine stock and all. It has an electric choke, so you would need to run a positive wire from something that gets turned on by the key. Since this car has sat for ages, just beware that it could be full of stale gas, or crud in the fuel system.

[dodge freak 2]

My opinion is one Holley carb makes more power than one Carter/Edelbrock carb BUT the Carter/Edelbrock seem to work better at idle and low rpms. Carter AVS were standard on many Chrysler motors, Holley were used to but not as much.

Since you are likely looking for a smooth running hassle free carb I would suggest a new Edelbrock or a older Carter. Ebay from time to time has new 4bbl Carters from the 90's that have been laying around in warehouses. Same carb just at a better price.

You understand it would be best to have the motor rebuilt, at the least a new timing chain might well be needed. Those chains can get very loose and even jump a tooth and be out of time. That is how my motor was when I got it. Motor would not start and when it finally did was very weak. I was young and cheap--still cheap but not young anymore. A new timing chain brought the old motor back to life.     

[73Chally]

I believe all the '70 383s came with Carters, so you might as well just get a new one, whatever brand, because what you have is not original.

[torredcuda]

The hp383 came with a Holley in `70 but I don`t have a listing for that number.

[missioncritical]

Thanks for the replies.  He previous owner said that the original carb was a Holley, as I believe I have the 383 HP version (orange ?).  I'm still researching that part.  The car recently had the fuel tank cleaned, sending unit replaced and fuel system cleaned out, so I'm OK there, but years of just sitting around took their toll on the carburetor.  I'll look at the 770, but wasn't the Holley 4160 the 'correct' Holley to use on a 383 ?

Checking the timing chain is a good idea as I have to replace the water pump anyway.  I do plan a complete rebuilt but was curious what the engine would run like if I did all of the 'external' things that I could do.

It would be nice to find the build sheet, but oh well.  I have to take pictures for insurance, so I'll post one when I get it.

-Kevin

[Chryco Psycho]

the factory Holley & yes the 383 & some 440 used a Holley in 70 were very small , typically 4160 series 600 CFM vacuum secondaries , the 383 will work better with a modern carb & larger cfm , the Holley 770 Avenger is a good choice but the Proform series carbs are generally cheaper & are more tunable & work better . Mancini has the best price on the Proform carbs

[torredcuda]

 
If you are going stock then get the correct 4160 Holley otherwise a nice Holley 750 vacuum secondary or go to a double pumper if you want performance over mileage.

[missioncritical]

OK, my new carb is in; its a 4160-style 600 CFM, but allows for some adjustability.  Visually its nearly identical to what I have now, but I have a question on the vacuum fittings.  My new carb has two vacuum fittings (one small, one large) on the front, and one large on the back.  There is also another on the metering plate on the top side.  The book labels this last port the distributor vacuum advance.

My old carb has different fitting locations: one in the back that goes to the air cleaner, another large one in the front that is used by the PCV valve, and another on the side that goes the distributor.  All of these are on the bottom of the carb.  Since my current carb is not the original, I don't know if its set up right anyway.

So, where do I connect my distributor vacuum advance on my new carb, on the metering plate or on the lower (manifold vacuum ?) ports.

Thanks for any advice.

-Kevin

[Chryco Psycho]

the vacuum advance for the dist is always connected to the side of the metering block & use a ported vacuum that increases with RPM