The 5.9 I am using came out of my daughters Durango w/80,000. You can’t hear **** inside a Durango. I never heard a blessed thing with the hood up while it was running n the Durango but it also had that massive and noisy fan. Now that it’s in my ‘79 Magnum, I hear a super faint lifter tick and each pulse on the header on the tubes.
The ‘79 and even more so on the earlier year vehicles all have a lack of sound deadening material. The firewall is the most notable place since your now hearing it only through the metal firewall and minor sound deadening material.
The Durango has much more sound deadened and other under hood items in the way.