RT magnum head question

I've always wondered if the Aussie EQ heads were the same casting. That maybe Mopar sold them the molds and they got rid of the "R/T" on the casting, changed the end of the cylinder head and called it their own. Or that EQ just flat copied the ports.

I've got a small valve set on the motor in my Duster. Got a lucky deal on them a bunch of years ago. I'm going to have to make a decision on whether or not I keep them once I do my G3 swap.