supercharger
 

What brand supercharger should i go with on my 2004 gt? I had a powerdyne on my 93gt and it was awesome! But powerdyne does not make them yet for the 2004.

I could be wrong, but the 04's are the exact same as the 03's. You should call them and double check, you probably just saw a typo or something.

If I had a choice...I'd take a look at the Saleen roots blower. Power is instant and consistant throughout the RPM band...IMO. Easy to install also...

You get a quality complete kit as long you pick any of the top, reputable manufacturers out there (Vortech, ATI/Procharger, Paxton, Kenne Bell, Saleen, etc.)
So really you need to answer these questions which will in turn help you decide:
What's your price range?
What is the car going to be used for?
What's your goal with the car?

You need to decide if you want to go with a centrifugal or a roots/twin screw type blower. I've been looking at the Kenne Belle 9 psi intercooled twin screw blower and the Vortech V2SQ. Centrifugal blowers make boost proportional to rpm, while roots and twin screw blowers have instant response and a pretty flat boost curve (constant regardless of rpm).

If I had the cash I would go the Kenne Bell route without hesitation!

blower for 04
 

How long can one expect a stock 4.6 gt engine to last with any type of blower. I want one for my 04 gt but don't want my engine to only last 20,000 miles as it has 300 miles now.

Re: blower for 04
 

to tell you the truth its a crap shoot

some last 50k with no problems and so last 5k miles

it depends on the tune how you drive and the shape the motor is in. and the gas you use . and yes it can let go with no sign of pinging

Yep, as long as you have a good tune it's all luck after that as long as you do your maintenance like you should and don't abuse the car. With no power adder the motor in my '00 GT didn't even last 50k miles.