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

cpearce said
My W2 head 408 made made really close to 550HP with a single 4bbl and TTI 1 5/8-1 3/4 stepped headers.

I recently came across a set of the 1 7/8 TTI W2 headers second hand for a great price. I picked them up, but I'm now on the fence. I'm not certain the gains warrant the effort to swap. Fitment with the stepped headers is great, I hope I'm not inviting a headache if I go to the larger tubes. The collectors change from 3" to 3.5" with the larger headers.

The car is also changing from 3.23 gears to either 3.73 or 3.91 gears, now that I am installing a Gear Vendors, so perhaps the bigger headers will benefit from the gear change?

Thoughts and opinions welcomed.

Headers are in great shape, just needing a little TLC and cleanup.

@Newbomb Turk, the LSA is 106.

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I recently swapped headers on my 418 stroker. Went from Doug’s 1 5/8 headers with 3 inch mufflers, to 1 3/4 to 1 7/8 step headers with same mufflers off of them.
The difference was dramatic, and at that point, that was the only change.
Based on the Et slips, difference was roughly 40 horsepower. About 10 more than what several people whose opinions I highly value suspectedI would see.
I was frankly surprised by the difference.
Think you would likely be happy with the swap.