Looks nice!
Sounds liike a vacuum leak,
I use starting fluid to spray where any vacuum leaks could be.
Just be carefull when spraying on hot areas it could possibly catch on fire.
WD-40,carb spray etc works also,but for me starting fluid will increase the idle easier,to find the exhaust leak.
Take off the intake manifold to look for any signs of a leak.
I like to use Hylomar on gaskets,fuel,oil, etc does not effect it.
Is your carb a known working carb?
MBHD
