Okay I did a few rough mockups. The 1850 Holley is unusable with this intake unless you can run a non-stock air cleaner. I think a person could mount double pumpers sideways with a lot of work and make a baseplate for a Mopar aircleaner with even more work. The 1850s mounted normal are too long and the air filter element would have to be where the fuel bowls are. If you mount the 1850 sideways then the diaphraghm is where the air filter wants to be. I deleted the dang photo but this setup would not work with the 69-71 air cleaner either.

Sheldon