What if it was really a 345..How about the "5.7" Hemi?
If it's really a 354, then wouldn't it be a 5.8?
My '62 and '66 Imperials that I daily drove in the 90s had firewall access to the heater core, and I replaced the cores in both of them. Took less time than an oil change. From front to back, those two cars were the easiest Mopars to work on I ever owned....and I've bitched about it before, but this seems like the correct forum-
Heater cores that require you to remove an under dash box that's fastened in with oddball fasteners in hidden locations and might require disconnecting the AC system.
Some even require removing the entire dash, when...
A simple, flat plate, bolted to the outside of the firewall would have given super easy access.
They would have saved millions of dollars. My father worked in the auto industry his whole life, by the end of his career he was the European Purchasing Manager for a company that supplied all manner of components to major manufacturers such as Nissan, Honda, Volvo etc.
He reckoned the car manufacturers would go through the whole car and look for savings, right down to the cent. Because of the huge volumes involved, over the course of a model's lifespan, these tiny savings add up to big dollars.