Too bad there seems to be no documentation of '70 aluminum intakes. I can see doubt that some '70 cars came with Edelbrocks if the motor had been modified over the years. But what about original untouched and unmodified motors? Why change intakes and modify nothing else on the motor?
My '70 Cuda with an A12 SPD has an aluminum intake. I bought it from the original owner in '89. It was 46,000 mile car with an unmodified untouched motor. I noticed the Eldebrock intake and asked about "the aluminum intake", he said it was cast iron. He never knew it was aluminum. Everything he had known about the '70 440-6 was it came with an iron intake and he thought the one on his car was iron cast by Edlebrock!
I know of a '70 RR with an aluminum intake, also with an unmodified untouched motor and a one owner car till '87. SPD was about a week before my Cuda.
There is a Moparts member that has a Cuda with a SPD a few months into '70 that was aluminum equipped.
How or when did a 440-6 motor get the aluminum intake?. My guess is hit or miss, and it was mostly miss. My '70 Super Bee with a SPD of 930 came with an iron intake.