340 idles at 1500 won't stay running in gear

Did you do the choke test? This costs nothing. No money, no labor. You simply ease the choke shut. No tearing anything down, no spending money. A five second check. .....but you tore something apart instead.

checked the choke early on I'll post pics of the soot I'm getting coming from the front of the intake manifold on the driver side. it starts up by the front corner and works its way back