Difference in manifolds

Right now my '74 318 has manifolds that came off a different 318. Don't know what year. Would 340 manifolds make a noticable difference in power? I know they flow better. Later this winter I may have a chance to get a pair. My engine also has a 340 cam, performer intake, and the 318 heads had some work done to them. Would this make a better combination over the 318 manifolds? With the 340 manifolds seal good to the 318 heads? Thanks
Author: admin