Winter Upgrades (Feedback wanted)

MOPARMAGA said
My 470 header swap from 2 inch fender well to 2.125 tti step under chassis headers was a 26 HP gain.
Surprisingly the fit perfectly in the car with torsion bars .

My engine builder estimated i'd see 15 to 20 hp going to the 2.125 TTI headers from the 2".

Sounds like he isn't far off.