Time for New vs. Rebuilding Carburetor for '71 road runner 383 4 Speed - Is My Carter AVS 4966S The Best Choice?

[road robert]

Hello Gang, my '71 road runner caught the bird flu and I don't know if it's fuel or ignition. I have a Carter AVS 4966S that was remanufactured then rebuilt recently (March 2023) by Dave Woodruff (Woodruff Carburetor Specialties advertised here at FBBO). At that time when I got it back I popped it in along with the distributor I sent him (he also put a curve in my distributor) and it ran great. But now after 2+ years my distributor is getting worn (shaft bushing) so I replaced it from halifaxhops (Ray Brenner also from FBBO).

My bird is stock except for a purple camshaft that I have no specs on - I just want it to start up cold and hot, run good from idle to wide open and overall for street cruising, NOT racing! So my questions are:

1. Which brand and model is the BEST carburetor for my '71 road runner 383 4 speed car?
2. Can I buy a brand new carb or is used (rebuilt/refurbished) better?

Thanks everyone!

Purple cam:

 

[torredcuda]

Original is always better IMO as most new ones are probably made overseas somewhere with cheaper parts and materials plus no mods needed depending on which new carb you bought - fuel line, adapters etc., I would get it rebuilt.

 

[Rapid Transit]

I put a Edelbrock 650 AVS2 on a 383 4 speed and it works great. There is a lot of buzz about this carb on the internet.
Improved technology over the old AVS and made in USA. I bought a 500 CFM for a 318. Haven't put it on yet but looking forward to ditching the junk yard Q jets that I've cobbled together and run for years.

 

[torredcuda]

Still actually made in the US, that`s surprising!

 

[Ferd]

Robert,
I’m having similar engine starting issues and thought I would make a few comments. I have a 383 with an Edelbrock model 1406 600cfm carburetor, and a distributor upgraded with a Petronix electronic kit. The camshaft is an aftermarket unit similar to the purple shaft. The engine will always start, but needs to crank typically about 10 seconds. I believe the longer duration of the camshaft is the sole reason for the longer cranking to fire the engine. The longer duration results in low vacuum at low speeds and this seems to affect starting. Your carburetor and distributor are probably in very good condition. Set your timing for 36 degrees total advance. Good luck with your car!

 

[road robert]

I found the smoking gun for my recent poor running problem - a bad plug wire resulting in a fouled plug. Thank you all I am all set car is running great again. I replaced the fouled spark plug #8 and all the wires (same set I purchased 5+ years agao from Lectric Limited):
SPARK PLUG WIRE SET - Lectric Limited

Using my Fluke DVM I ohmed out all the new wires for reference, they range from ~ 10K ohms to 20K ohms depemding on length. The old set #8 wire has NO continuity and is definately bad, it is the one with the 135 degree angled long boot so need to be extra careful that it is pushed all the way onto the spark plug (hear & feel the click). THe new set comes with grease for the boot to help slide onto plugs, I put a light coating around the ceramic part of the plug so it doesn't get on the contacts.

*Initial timing at idle ~ 10 degrees BTC, i have the ported vaccum line plugged running without it, I will unplug and connect to distrubutor to see if there's any difference. Not sure what the "optimum" position for the distributor timing is but it runs great where it currently is...