Best CFM carb for a 416????

For the OP, look back by searching post by OU812 and read the rhs headed 410 from about 2 years ago. There are a few threads. The last update a 750dp was swapped to a 950hp on the 485hp. The change was in the 5-8hp range.

Draw a correlation or extrapolate from that what you will. It's not uncommon for stuff in the 500hp range to pick up 5+ hp with this swap. Some make more...