Headers or Not?

I have a 2000 Pontiac Firehawk with 13,500 Original miles on it. I am wanting to install headers on it. Will putting headers on it hurt the rarity of this Car? There were not many Firehawks Made and it is a numbered Car. Someday, It may go up in Value, Would Headers hurt to chance of this happening? Just wanting some opinions on this.

Theoretically, yes, it will affect value, either due to the loss of the parts or because the buyer will think that you have raced/abused the car.

Just keep all the original parts, manifolds, pipes etc. If necessary, you can always reinstall them when you sell the car, or at least provide them to the buyer, so you can preserve the originality of the car.

I second that. Lots of people keep the original parts and sell them later with the vehicle if needed.