New 408 stroker runs rough at idle

What can you adjust the idle down to?
Have you tried turning the idle mix screws in all the way to ensure the engine dies? (Lightly until they bottom out)
Does this have a choke? is it open?
have you put a temp gun on every cyl and make sure all 8 are firing?
Ignition system ran flawlessly on the other engine?
The idle speed goes down to about 350 r
What can you adjust the idle down to?
Have you tried turning the idle mix screws in all the way to ensure the engine dies? (Lightly until they bottom out)
Does this have a choke? is it open?
have you put a temp gun on every cyl and make sure all 8 are firing?
Ignition system ran flawlessly on the other engine?
so I can turn the idle speed screw down to about 350-400 rpm then it dies. But yes I turned the idle mixture screws in until they stopped, and it stays running, doesn’t effect idle speed at all. The choke does open on its own all the way. I disabled the spark at each cylinder, and found cylinders 1 and 3, the engine runs noticeably worse, all other 6 cylinders, the engine runs exactly the same when they’re disabled. There is a pretty hot spark at each cylinder. This is an all new ignition system, this is the only vehicle I ran it on.