engine mod question for 4.6

You say you have 10k to spend???? You can get about 400 wheel horsepower for 3600. The vortec v3 is 3600$ over at americanmuscle.com. If you look hard enough you can actually find a used kit for alot cheaper. Spend the rest of the money on supporting parts such as clutch, tranny, block and you can see about 550 to the wheels with the vortec.

holy s*** $10k for a budget? im thinkin a 2v bottom end with a 4v top end 4.6 build with the new humongous whipple blower for a GOOD 800-900hp.

If you've worked on 5.4's, you can work on a 4.6.. It's the same engine, one just had more cubes.

KBExp is basically correct: Although the block, crank and rods (and other sundry parts) are different between the 5.4 and the 4.6, if you know the former you know the latter.

Why did you get the 03 GT for "extremely cheap"? What's wrong with it? Has it been hit? Damaged? Is it worn or tired? How many miles? What trans does it have and is it in good shape?

How much of your budget are you going to have to put into it to make it "right"? Brakes, suspension, clutch, rear end, chassis etc...?

400rwHP isn't that much and is doable on a stock bottom end with a low-pressure (e.g. 9-psi on a small KB blower...) supercharger setup. But again, if the car was "extremely cheap", was it so partly because the engine is hurt or has very high miles? If you want a reliable 400rwHP you need, at the very least, a reasonably fresh bottom end. This could mean high-ish miles on a well maintained car but a "extremely cheap" car would make me wonder.