1 3/4" Headers Verses 1 7/8" on a Healthy 408....Is There a Big Difference??

i have no answer to your question, but would love to see a test.....i´m in the middle of installing the hedman 1 7/8" in my car....don´t know when i´ll be able to go to a track this year. Motor is also disassembled, crank thrust bearing damaged - waiting for a new crank. What kind of collector extensions do you run with your current headers?

Michael