408 stroker header size

So mopac has either the moroso 8 quarts or mildon 8 quarts only with new pick ups and felpro gaskets which one will fit better ? I'l look into Pro stock thanks. I'm in Vancouver Canada. But not a fan of going over to pick up parts and paying duty etc
I ship many things to a warehouse on American side in Montana. When you bring across all you pay is GST, no duty.