I have a later head (C1AE casting= 1961) out of my '62 f100 223. I bought an Edmunds aluminum dual carb intake for an earlier 223. It has "52 Ford 6" cast on the bottom. The port sizes are definitely smaller on the Edmunds intake compared to my head and the stock 1961 intake. I'm gonna go measure 'em now...
Stock head with C1AE casting intake ports: 1.615"
Edmunds intake ports: 1.420"
Stock intake with C0AE casting (1960) ports: 1.610"
My plan was to do sort of a "mileage maker" set up and run the early edmunds with dual carbs and small jets. I'd get the look of an early hopped up straight 6 in my truck without the crappy mileage from dual carb set ups. Since the intake ports are smaller, there shouldn't be too much of a flow problem with the flow direction going from little to big (ie. it won't hit a big lip as if it was going the other direction). I wasn't going to port match the intake to the head, even though there is plenty of meat on the aluminum intake to do it if I wanted. I recently talked to an old hot rodder that runs a bonneville car with a hopped up early ford 4 banger. He said that he has a friend that did the exact same thing (early dual carb intake with late heads on a 223 inline 6) and he got 30 mpg.
Don't get me wrong, i'm not a tree hugging hippie trying to feel better about myself by squeezing the most mileage that i can out my old truck. I plan on making this a daily driver and i drive 30 miles each way to work every day. I'm not looking to get 30 mpg, just not 8! I'm doing an early 60's style mild custom with gold scallops on white, maybe an old rotary phone and tube tv, etc.
Shane