I did try a smaller Indy single plane on the Hemi when it was on the Dyno. It gave up somewhere in the nieghbors of 50-60 hp compared to the Weiand TR. I looked at the bigger manifold but didn't like the pricetag. I ended up giving the manifold to Dragula, I don't remember if it worked for him or if he went bigger
The carb I used was a BG-1140cfm unit and it was to small.