Pontiac running 2009 big cam idle

1964 Pontiac Tempest, 2dr Post, 455 .040 over, 4X heads, Comp XE274 cam,Performer RPM manifold w/ Edelbrock Performer 800cfm, Full Pypes X exhaust with RacePro mufflers. Engine has Holley 3130/750 now and different timing set up. Made huge difference. I could never get the Edelbrock carb to work right. And yes the Mr Gasket header gasket on the driver side was leaking just 40 minutes after break in.