Stalling in gear

[Hood]

Engine idles great in park/neutral but stalls almost instantly when put into drive or reverse. Is this a carburetor or fuel issue?  I changed the fuel filter but it didn't help. 

[Cuda Cody]

What carburetor are you using?

[Chryco Psycho]

Generally carb issue  , lower vacuum , the power valve opens up or the metering rods rise & it stalls out  , although I have seen the timing change in gear causing it to stall

[Bullitt-]

 Larry,  1st check for a vacuum leak

Then try backing off the idle screw & advance timing a couple of degrees.
Use a vacuum gauge to find max vacuum at idle & you may solve this issue.

Over exposed idle transition slots will cause one to stumble or die under load .
   about half way down in this article 
http://www.superchevy.com/how-to/45638/

Item #2 is a transition slot

[Hood]

What carburetor are you using?

I have a thermoquad 850

[Hood]

Wade.... I'll check for a vacuum leak first and then take it from there.

[Hood]

Chryco.... I'll check the carb and look for anything binding or loose.

[MoparLeo]

This question should have been asked.
Did this problem all of a sudden show itself ? Were there any changes or adjustments done on the car before this happened ?
Transmission/torque converter ?

[RUNCHARGER]

What Mopar Leo said. If you just installed a wilder camshaft and this started happening the car needs more initial distributor advance and the total advance limited.
If no changes were made and this just started happening it means other things, one thing to look for in that case would be a vacuum leak.

[Hood]

No changes were made....other than an oil change.
I'm thinking it could be a vacuum leak or possibly something lodged in the carburetor. 

It started to do this last fall just before I stored the car.
Last month when I started it up from winter storage the engine ran perfect. I took it for a short drive and it didn't hesitate or stall.

It sat unstarted for about ten days, then 2 days ago after starting it up it started stalling when backing out of the garage, just like last fall. I changed the fuel filter, but nothing changed.

Other than the distributor hoses and the brake vacuum booster, where else could a vacuum leak be occurring?

Should I spray some carb cleaner around the base of the carburetor while the engine is idling?

[MoparLeo]

Never spray anything flammable on your intake !  Just a fire looking to happen.
You are just looking for a change in RPM.
Use a spray bottle with water. Just look for an RPM drop.
Pull the spark plugs and inspect for fouling, etc...
Just for more info, what exactly are you running ? Stock small block, big block ? If not stock, what is the build combo and any trans mods done.
More details help make better diagnosis.

[Hood]

MoparLeo...I'm running a stock 1973 340 and nothing has been done to the 727 transmission. The spark plugs are 14 years old with 1,750 miles on them. I'll pull and clean them the next chance that I get. The timing was set 13 years ago at 36° at 3,000 rpms. It has ran excellent with that timing.  Any other ideas to look for are welcomed.

[Bullitt-]

  I once found the hose to the PCV split at one end on some Mopar, cut off about 1/2-inch & reinstalled.
  Also on a 90's Dakota that was running bad and stalling I tracked it down to a dirty PCV valve that wasn't closing completely at idle.
  Don't recall any vacuum leaks otherwise... Tried spaying carburetor cleaner around on a couple of occasions & found it was getting sucked into the carb and revving up giving false indication.   

[dodj]

Other than the distributor hoses and the brake vacuum booster, where else could a vacuum leak be occurring?

Between the intake and cyl head. I had a leak there once on a 318. Can't remember for sure but I think back then - about 15 yrs ago - I used WD40 sprayed at each intake runner.
Base of the carb. Maybe check if the mounting nuts are snug?

[MoparLeo]

Recheck your 14 year old tune.. Plugs and timing, carb adjust. Nothing lasts forever. Fresh fuel ?
Mileage is not the factor.