I think I havefinally found the part of parts.A dual quad intake manifold for the 390.DSCmotorsports.com has the factory one,it says its for the FE including the 390, part number-C3AZ-K I have been looking every where edelbrock,offenhauser,holly,weiliend,no luck hard to find big block 390s they want 450.00 + shipping thats anOEM.If someone Knows who I can get a cheaper one from let me Know.Im getting 9 mpg now so whats 5. Dan