Manifolds are part of the exhaust, so restrictive ports or manifolds equate to about the same. To overcome that a bit the exhaust seats can be cut to 40° which aids the low lift flow. This aids blowdown to get the scavenge cycle going strong.
Now with W2 heads on a 416-435 seems like a pretty straightforward build, cam is gonna be the most tricky part to work with the exhaust manifold restriction and lack of collector.