New 408 stroker runs rough at idle

Ok so I replaced the plugs, checked the total timing and I am getting 32 degrees at 3500 rpm. I did have to bump the distributer down a little because as I was revving it up it was starting to creep past 34 degrees. But now it goes 32 degrees max. At idle it now reads about 12 degrees. It still actually does seem to miss even when you rev it. It just seems to run rougher at idle. I sprayed carb cleaner around the intake gasket area on both sides, sprayed carb cleaner at the vacuum line connections at both the pcv valve port and brake booster hose where it connects to the intake. I also sprayed carb cleaner around the base where the carb mounts to the intake manifold and the idle speed didn’t change a bit. I also clamped both the vacuum line that runs to the pcv valve, and the brake booster with no change in idle or vacuum readings. I also plugged both valve cover holes to see if the crankcase was going to pull a vacuum, and it builds a small amount of pressure within sealing it off for 3 seconds. I honestly can’t find a vacuum leak on it.
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?