Pure Shadow77

Question:

1. does it make a big difference in the car performance?
2. is it easy enough to install myself or would it be better to have a pro. do it?
3. which intake manifold would be best on a 2003 GT? (i.e. cobra, typhoon, etc...)

WhiteFoxGT

1. No
2. Yes its rather easy with basic socket / wrench set
3. Stock PI manifold with a good plenum / TB

IMO, anything aftermarket isnt going to benefit much in the HP department, unless you are running some decent boost or really hi-flow heads...

01GT4.6

ditto

BOSTANG

Save your money and go stock.

Eagle2000GT

+1 Not worth the money unless you're running nitrous and need a stronger intake. Besides most after market intake manifolds make horsepower at rpms higher than stock heads can use. And this is at the expense of mid-range torque.