350 2bbl, worth 4bbl swap?

[Bigdually]

The 350 in my 73 C60 dump truck has a 2bbl manifold and carb. As I'm working on the truck I'm realizing this would be a great time to swap manifolds, I just have questions as to if it's worth it. I know the truck 350s are low compression small valve engines made to run hard for a long time. I was considering a Performer EPS manifold, made for torque in the range the engine will be running, and I have a spare 1406 carb laying around.

Anyone have experience in this swap? Are there any real world gains to be had from going 4bbl or will I just be dropping my mpgs?

Merry Christmas!