Questions on Intake and holley

I recieved a 4 BBL intake recently that I am trying to ID. The casting number is 2531 15-2 and the other is 03259.

Also with the intake, is a Holley with: List 4366 stamped on it. From what I have found so far, this carb may have come on Imperials with a 440. I can't find what the CFM is for it though.

I bought these to put on a 318, but I am unsure of if the carb is to big, and if the intake is for a big block or not...

Does anyone know of some sites or anywhere that I can get more info?

thanks

I just received an email from Holley, and the carb did indeed come on 1970 imperials with a 440, and they are rated at 330 cfm, in case anyone else was curious. I would still like to find out about the intake though...