the 390 Police intakes were iron, same intake as the 352/390 4v.
Do you mean the 352/360hp HiPo intake?
Or the 390/375hp or 406/385hp or 427/410hp Lo Riser intake?
These are all the same, except the 352/360 intake - it is lower in height.
All these are aluminum and have the oil filler in front.
Or, the 428 Police intake, from 66-68, also used on some 67 Shelby and 68 427/390hp Cougars. It is aluminum, and higher than the Lo Riser intake, has more top end. The oil filler tube area is cast in but not drilled out, so you could machine this intake for the tube [we did ours that way].
What's the application you have in mind?