Stalls on idle in gear

Working on my car still lol like we all are....

Here is the situation: My 340 has a decent lumpy cam. It came with the car so I do not know the lift on it... Others that have been working or hearing it seem to think its a street/strip purple cam in the 455 t0 485 range...

Earlier this year I had to replace a rod and lifter and most recently changed the timing chain as it was stretched more then it should of been... We detected this when trying to set up the timing.. We noticed when moving the crank the rotor was lagging and not moving soon enough...

So the current situation is this:

Car is running nice once its moving along. Tons of RPM and want to go go go... but when it warms up or if the day is hot I cannot get it to idle in gear... always have to pop it into neutral when approaching stop light or sign... PIA...

The carb is a 600 Holley with vac secondaries. Is been pulled apart cleaned and put back together. Mechanic says its good...

[ I do notice the mixture screws on the side of the bowls are not very responsive when turning them ]???

Pulled the plugs and they are a golden brown on all of them.. I suspect this it dry and means the setup is too lean...??

I do not have a mechanical adjustment distributor so the timing is set like normal off the damper with gun.

I have done a ton of reading here on FABO .. From what I read I suspect 3 things

1: Carb mixture screws and idle circuit are not working right... [ this might include the accelerator pump ]

2: Timing : need a distributor that can be curved and have mechanical advance setup... [ I can have mine taken into Jim Speed shop in London Ontario and they can curve the factory distibutor for 75 ]

3: a fuel issue , maybe gas is too hot entering the carb on low idle ?

My mechanic wants to up the jet size from 70 to 72 but he already went from 68 to 70.... I think jumping to more sizes will just increase the gas usage and not correct the stalling...

I was recently at the Bothwell Carshow in Bothwell Ontario and chatted with a carb expert.. He says I need to get the carb working first before
determining any further.. He suspects the front idle circuit is dirty or plugged in one of the areas... this is why the mixture screws are not responsive.

Okay enough of my rant...... im looking for your input and experience too so I can further my testing...

Hoping to fix this before MoParFest..... :) !!!!!

thanks in advance FABO

Houston

:burnout: