What is the Best for whp gains

[1band1t-MS]

I have a 01 M6 Trans am and it have as of right now a k&n air filter and flowmaster EX. I know I need to get a new lid, L T Headers. How ever I am not shure if I should get A Y-pipe are true duels or something els. I dont care how loud it is just want what gives me the most hp. And I am also wondering what brand is the best for each to get the most hp gains? Dose not mater how much the cost. And how much of a hp gain will I get? Any info will be great thanks. I am also going to install a new clutch to. I am thinking of going with a Z 06 Clutch are a stage 2 but not shure yet. Need to find out more facts. So if you have any info good are bad please tell. All sugestions are welcome.Thanks.

[nhraformula]

duals will give a better gain than a catback, but not that much.
for a good set up, get long tube headers and a hooker or magnaflow exhaust.

[1band1t-MS]

ok thanks alot for the info.