Scored Offy dual quad intake for my 392 WEDGE project!

I've had issues with this manifold used with large port(360) heads..
There's simply not enough meat on the ports (floor side) for adequate gasket sealing.
I've seen these manifolds welded and machined to build up more surface area for gasket sealing on the floor side...
If the OP is gonna have a machine shop mill the bolt hole angles, you might look into welding the ports. Then have the intake face milled flat and perform a gasket matched port.
Laying an intake gasket in the head and then on the manifold will help see any issues.