Doing 4.06 gears if you can still find them and a limited slip will really make the car act differently.. for the better. wont really make it faster in a straight line, but if you take the turns you can usually power in and out of them faster.
Full exhaust, high flow SVT cat, with the SVT header. Air intake, stage 1 cams with adjustable gears, tune, go with a FRPP suspension upgrades and swaybars. If you still want more after that then get a used ford racing head with stage 2 or 3 cams. can go with a individual runner / TB intake setup. with the new head you can deck it some and raise your compression. Want more then that then tare the block apart upgrade the pistons deck the block. raise your compression some more.
follow IMINHELL's posts... think he posted recently what all he did to get his NA built motor.
2001 ZX3 2.0L Zetec-
Hatch Nation #42
Going through Rebuild See "The TICK Build Thread" for details (http://www.focusfanatics.com/forum/showthread.php?t=289168&referrerid=62897)