When my dyno is up and running (hopefully in a month or so) we will be testing header sizes. Since I’ve already done a bunch of it I’m 99% sure of the outcome. Spoiler alert...I’ve never seen a good set of big headers lose power anywhere.
If you watch Engine Masters you can go back and look at any of the small block mopar tests they have done. Every one of them has been tested with Hooker 5303 headers. That’s a 1 7/8 primary tube. They may still have the 3 inch collectors on them, but I use 3.5 inch collectors because I run mufflers.
