couple questions

#1 I am looking for a carb recomendation. 70 duster 340 10.5-1 comp. big valve 915 j heads gasket matched tti headers mp 509 lift mech cam and edelbrock performer dual plane.

#2 the intake doesnt cover what I think is the exhaust crossover, the gasket covers it but the intake doesnt. Is this a problem?

#3 Last question I promise (for now) does anyone know what my valve lash with the mopar performance 509 mechanical cam and ductile iron adjustable rockes should be?

Thanks guys
Ron