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

it was a 235/ 273, had a cam dynamics stocker cam, stock comp ratio, stock rods, heads and intake manifold, carb. 5.57 gear 28 "x 8" tires. stock 4 speed trans . 3150# race weight. class was J/S. yes both sets were fenderwell style. it was an eye opener, since mopar said they were too big. I think outside the box a lot.