HELP! 66 cuda idles fine, but not when in gear

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Challngd73

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Hi everyone, been here for years, don’t post much...but I need some help. I have a 66 barracuda with a 408 stroker. I have a small Holley 600 carb on it. Motor has about 500 miles or so and she will fire right up, and idle great and stays running fine. It runs like a beast at wide open throttle, part throttle, you name it. The problem occurs whenever I have to slow down and stop at stops signs or lights. The car wants to stall as soon as I stop. If I put it in neutral, it’s fine, and then I put it in gear and she goes fine. It’s a very annoying problem that I can’t seem to solve, no matter what I set the idle at. Any solutions?? Please!
 
You didn't mention motor details, cam, converter etc but you might try opening up the mixture screws a quarter at a time and see if that helps. Cammed up motors usually like a richer idle. Seems like a awful small carb though. Your probably leaving some performance on the table, but I don't know your intended use.
 
Sorry it’s a 2500 stall, flat tappet cam .545 intake .545 exhaust 241 intake 247 exhaust @ .050 110 degree lobe separation. I had a 850 duel feed proform and it ran waaaay to rich. She’s just a fun cruiser.
 
Would idle with the other carb, but after a few drives she wouldn’t fire and I yanked the plugs and they were quite fouled
 
Car is being used in a movie and filming starts Friday so trying to sort it out before then.
 
I had a GM 350 sort of do that but not exactly - tried everything fuel wise turned out to be a bad distributor
 
I put an edelbrock on and ended the battle...
May not be all there, but its certainly driveable at least.
 
What's your idle timing? and are you running a PCV? and is your Vcan hooked to the Sparkport?
If you run too much idle-timing the transfers slots will be too far closed, making her especially sensitive to fuel level changes.

You can make it idle with 25* but this is often the result of doing so.
 
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Forgive my ignorance, with the pcv and vcan and spark port. This is my setup if you can tell from these pics
 
Move the PVC to the carb, you are dumping all the blow by oil vaper into #8 cyl. Not that it will help your idle situation but in the long run it will help overall.
 
If the intermediate shaft was installed correctly, by the look of the vcan, youve got alot of timing in it. And as was said, move the 2 large vaccum lines. Pcv should be at carb, booster should be full manifold vaccum. Im not a big fan of edelbrock carbs, but thats just me. A 700 or 750 holley would be my choice. My 360 with a similar spec cam, 3500 converter, likes to idle in park or neutral around 1k. In gear is @650 or so. A properly curved distributor will make a huge diffrence. Hallifax hops did one for me, and its great and price was extremely reasonable
 
I dont imagine that cam has alot of manifold vaccum. Guessing initial timing should be 16 degrees or so( every engine is different) i would think it would run better if total timing was in by 2800-3000.. and possibly more converter
 
Ah. Duh. Vcan, got it. I’m sure I’m coming pretty ignorant with all this but when I was a kid and tuned my old Chevy motors I was pretty simplistic with it, no vacuum to the distributor, timing light, 6 degrees or what not. Obviously to really dial it in there is a bit more I need to learn.
 
I found the info I need to properly do the timing. I’ll give it a go tomorrow. Thank you all for the informative responses.
 
I was just looking over your pictures, and I found another thing you can try. Right now you have the vacuum advance hooked up to the ported outlet on the carburetor, pull that off and hook it up to the vacuum Port near the base plate underneath the front fuel bowl. Plug the one you currently have the hose coming out of. Bet you a box of donuts that helps.
 
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