4-Door with 340 from the factory?

They did make some W2 heads with dual exhaust bolts holes. So if they had the ECONO style heads the manifolds would bolt on. The port mismatch would be terrible. But I assure you it never came with W2 heads. W2 was a prototype only that was not used used in production.
They also made cast iron W2 intakes with 360 PN#s on them . I have one .