What gains will I see if I install headers on my stock 99 ta

[Street Fighter]

I have a 99 ta with 50,000 miles on it, I am thinking about installing headers, what horsepower increase will I see with tuning, I have a performance muffler but stock exhaust pipe.it's not a racer just like going fast.

[SMWS6TA]

maybe 20-25 with a tune on stock engine. Headers really come in play when you do heads and cam.

[98TransAmWs-6]

If you are doing headers it's definitely worth upgrading the whole exhaust not just the headers. It will sound better, get better flow, and might pick up a few more hp since there is no bottleneck. Scott is right though it comes more into play when you do other mods such as cam and heads.

[DarrenWS6]

I had a good amount of things done at once. Started as GMMG catback and SLP lid. I had 1.75" longtube headers, ORY, LS6 intake, and EGR/A.I.R delete. Dyno tuned to dial everything in, my 2000 LS1 is pushing 360rwhp and 367ft lbs torque. So I gained about 60 horses doing all this at once and tuned.