Its a super clean to the point it looks new '74 360 automatic Thermoquad I got on my Lebaron that just refuses to idle right and stalls sometimes when its up to operating temp. Punch it down it goes like a scalded dog, cleans out and then will idle fine for awhile. Driving me crazy I've had it apart twice and I'm positive all the air bleeds and fuel circuits are wide open on the idle side. I even drilled two 1/8" holes in the front of the primarys to try and richen up. Pulled one spark plug out which have been in there for about 3000 miles and it was white, almost new looking made me think is this thing super lean actually. I threw a vac gauge on it and I had 15 and if I turned the idle up to around 1200rpm I got 17 max. Turned the idle mixture screws all over the spectrum in and out and couldnt achieve anymore vac. Plugged each vac line one at a time to see if it changed it did not. Only one I didnt plug was the brake booster. It always starts back up immediately after it stalls with no trouble. Could it be the o-ring or seals that seal off the primary venturi and idle fuel feeds of the aluminum top at the bottom of the plastic fuel bowl section? Of course it has a fresh rebuild kit in it but could it be that the heat of the engine is swelling or flexing it enough at temp to cause a problem? What do they do when you lose seal there? Acts just like a carb with plugged idle circuits or one with a bad vac leak. Which I could find neither of on it. Its a stock iron intake or I would have swapped a known good AVS on it by now and saved myself the trouble of stressing over it trying to get ready for the NATS this weekend. Ugh. Any ideas fellas?

Oh and I'm 1 1/2 turns up on the primary jet needles. They call it the "tree" right?

And the motor combo is 2.02 J heads cut .060 with .039 Felpro gaskets and a OE replacement 340 4V camshaft and a stock iron TQ intake on top of my stock bore '78 318.

That carb should run fine as-is with a mild cam like that. My guess is a vacuum leak or the wells may be leaking. I think drilling holes was a mistake.

I will be at the nationals on saturday and wouldnt mind taking a look if you bring it along. I will PM you my cell #.

Try moving the throttle shaft up and down while it is running at idle. The holes in the aluminum base that the shaft goes through sometimes elongate and cause a vacuum leak. In the day we used to drill each side and put in bushings to seal to the shaft better.

My guess would also be leaking jet wells or a vacuum leak most likely caused by a worn throttle shaft. You did make sure to put those jet o-rings back in properly right?

Drilling the holes will lean it out.

Throttle shafts wear the most on the passenger side.

Ethanol blends make it run leaner. Less BTU's in ethanol.

Your vacuum numbers are too low.