Manifold heights

Not a new subject, but I wanted to swap a Mopar dual plane (RPM) to a single plane M1, and did some measuring to see if it would fit under the stock hood.
It would fit with a drop base K&N base and 3 inch filter, but nothing but a paper carb gasket , no insulator 1/4 inch gasket like I had on the dual plane.
I put the intakes on a mock up 440, with no gaskets. The M1 measured 5 inches, the Mopar dual plane measured almost 4 3/4, the Holley street dominator measured 4 inches, and a edelbrock street master measured 3 1/8.
This is what I came up with. I went with the street dominator.
I also swapped to a Hughes Engines valley pan.
Hope this helps?

Forgot a couple things. This is on a 1966 Coronet, and with the straightedge on the carb base, I measured down to the front pan rail.
When I had the M1 on, I mocked up the Holley carb and air cleaner I used on the Mopar dual plane, and put a piece of orange clay on top of the air cleaner, closed the hood. It squashed to .120 clearance.

You said you put a manifold on a ‘mock up 440’ But never did say what engine you have in your coronet, but I’m assuming it’s a 440. Regardless here is a shoot out that shows the different manifold heights for a 383/400 maybe it can help you?
https://www.hotrod.com/articles/hrdp-0712-mopar-intake-manifold-comparo/

And for what it’s worth I think the rpm performer got better torque performance numbers than the M1, at least on the 383 anyway and maybe only a couple HP less. Might not be worth the change?

Thanks 4mulas, appreciate the info. Yes the engine in the coronet is a 440. I put the Holley SD on and it seems to like it. I think the M1 is too much for my mild combo, and I don’t want to put the SS scoop on, not yet anyway.

NICE

Thanks!