There has been an issue with the Holley 770 Avenger carburetors..
Everything can be running fine, shut it down and then it wouldn't start even after several minutes of turning the engine over...
Acting like no spark or no fuel??
This happened on a friends RoadRunner 383 with the 770 Avenger.
I pulled the air cleaner and found that the choke blade was all the way closed even though the engine was warm.
Next I pushed hard on the choke blade back to reopen, hit the key the engine fired rite up..
I installed the Avenger many years back and never had this happen before, the RoadRunner always started rite up..
Don't know why the choke blade was forced closed but this happened a couple of months ago and everything has been fine since...

Juts my $0.02...