Carb Selection for 340 Engine

[gzig5]

So I just brought the car home last Saturday.  The previous week, we couldn't get it to run with the Holley 4165 650 spreadbore that was on it because it was full of rusty fuel from sitting for years. The PO threw a 4150 double pumper 650 (R6708-1) on it that was on his shelf, but it still wouldn't run.  I got it home, replaced the damaged fuel pump and got it to start, but it was surging and popping bad.  Pig rich, stunk up the garage.  Took the carb off and after some research (haven't touched a carburetor in 25 years) set the various idle adjustment screws and got it to idle semi-normally, but the carb was still spitting fuel out of the secondary squirters and pooling fuel when it wasn't running.  Also leaking on each end. So obviously needs a rebuild and the kit is on the way.  No idea how far gone this carb is but we'll see.

Now, lets consider this carb didn't exist and you have my '73 Cuda with 340, automatic, 3.55 gear (I think), headers, stock-ish ignition, stock or mild cam, and Edelbrock LD4B intake, what new carb would go with and why?  I'll be running as is for the near future just puttering around as I work on the suspension and other bits.  More engine mods will/may come as I make progress.  Hope to eventually see at least 400 Hp with this motor which will likely require a different cam and heads among other things.  Autocross events and Road America are on the bucket list, not so much drag racing but maybe some if I catch the bug.  Is there a carb that will work with what I have as well as where I hope to go?

Greg

[LinceCuda]

Why not just put a Carter Thermoquad back on it'll handle what you have planned. You need a 6319s 340 automatic car carb I saw one that was complete and needing a rebuilt on ebay just yesterday. Buy it send it to me I'll make run like new or restore to factory new looking as well more money though. Here's one I did 2 weeks ago.

[kathyscuda]

the best carb choice I made was having my orig AVS rebuilt.

[RUNCHARGER]

I'm a big TQ fan as well but for a bit of a warmed up 340 a 650 DP would fill the bill pretty well. I would dip it in carb cleaner for a while and rebuild it to original Holley specs and see how it works out for you.

[Cudajason]

I would have thought either of those Holleys would have been fine.

I run a 750 Vac sec on my 360, and it works fine, once you get it tuned, but that is true with any carb.

In all honesty, I have been casually looking for a 650, because I think it may actually run better with the smaller carb.

Jason   

[Katfish]

I'd get a Fitech fuel injection system and not look back.
Carb will be nothing but trouble, no matter what brand/type you end up with.

[Chryco Psycho]

did you get the old fuel out of the tank & lines & get fresh fuel in there , nothing will run right on old fuel
Either of the carbs you have should work well

[gzig5]

did you get the old fuel out of the tank & lines & get fresh fuel in there , nothing will run right on old fuel
Either of the carbs you have should work well

I'm working on the cleanup of the tank and lines but haven't had much free time this week.  I won't be running off the tank until that is all squared away. 

I hadn't considered a Carter, but that may be a viable path if this 650 doesn't work out.  I guess just about every pic I see has Holley carbs on top of the intake.

I definitely would like to try FI but it isn't in my budget at this point.  I am looking into getting an FI ready tank and see if I can run the standard fuel pump with it on the carb until the budget allows the FI setup.  On the other hand, I think most of the systems will work with an external electric fuel pump?

[Chryco Psycho]

Yes you can run an external pump , but they are quieter & run cooler in tank

[blown motor]

I'd get a Fitech fuel injection system and not look back.
Carb will be nothing but trouble, no matter what brand/type you end up with.

I have a 650 Edelbrock on my 340. We rebuilt it and tuned it 5 years ago when we rebuilt the engine. Haven't touched it since. It runs awesome.

[gzig5]

So with a carb on an automatic, vacuum secondaries verses mechanical is a wash or one has some sort of advantage? Again, on the street and occasional road track.

[CudaHead]

I had lots of problems with my stock AVS on my 340. I bought the Edelbrock AVS2 and installed it. It runs great now.

[Shane Kelley]

On a stock or mild built automatic I like the vacuum secondary the best. Mechanical secondaries can cause a bog in those situations. I really like the QFT carbs. Something like a 650 would work out really nice. IMO   I'm running a 650 vacuum secondary on one of my 340's with a automatic and 3.55's that my wife drives all the time. Trouble free.
But like Chryco said. Don't run off any of your old fuel system.  Tanks are cheap.  Replace it and I would replace the line also. You don't want to take a chance and gunk up a brand new carb.

[Brads70]

   I'm also running a quickfuel carb. Best carb I've ever owned.

[RUNCHARGER]

I have to agree with a vacuum secondary on a stockish automatic and a double pumper on a manual especially if it is warmed up a bit. You might be best off pulling the tank so you can pull the sender out and have a look in there. Body fuel lines are bit of a challenge to replace when the car is assembled but if there is any concern it is not something to take a chance with. Pulling the fuel filter should give you a hint of what is in the lines and tank.