69 273 Head and Intake

First, "I" would find out the reason Edelbrock wants to use the 340/360 heads. If it's "JUST" port size, I'm like @toolmanmike, I see no reason why it won't work. Chrysler did that mismatch on millions of engines right from the factory. But FIND OUT first. Edelbrock may have another reason...you never know, so confirm that first. If port size their only reasoning, then I think you're good.