Currently on my 80' Pinto and I know for sure its not stock.
Has this number on the front far side ( 1-3-4-209EE9425-AA )
My guess is that it came off a foxbody mustang or thunderbird
No other topics of decoding intake numbers on here and no help searching the web
It has oval ports, not a square top mount like a stock pinto manifold and has a top mount that would fit a Holley 2300, Motorcraft 2100/2150 etc...