It's a 4/71 and those are likely powder coated stainless or aluminum tubes.Heh, the boat.
You take a 6/71 and it appears to be about a 1:1 drive ratio on it.....then shove all that air thru 2 (looks about like) 1 1/2 inch silicone hoses ?
Yea, brilliant.
Ever see the openings on a 6/71 lower intake ?
That image should be in a dictionary right after the word "Restriction".
Given that is a nailhead Buick it's actually a kind of a clever way to take advantage of the tiny valve sizes.
Since not a freeloader, probably the most famous nailhead that ever was: