okay, so you have a 93-01 impreza. you want to look cool, so you want to have the look of the 1999-2001 2.5RS, or STi version 6 impreza.
first of all
1999 usdm 2.5RS = JDM sti version 5 (no little holes for lip spoiler-iirc but same look as V6)
2000-2001 = JDM sti version 6. has little square holes to mount OEM JDM lip spoiler with
okay. so lets start with the bumper first of all:
any GC8 (1993-2001) bumper is interchangabble with any other GC8 bumper. that is fact, if you ask why, i will not respond.
i own a 1993 impreza L, i have sti v6 complete front end on my own car. so yes. i have done this before.
you will need for converison from 1993->2001 2.5 RS bumper
1 bumper skin from 2000-2001 2.5 RS (sedan = coupe) ~$220 @ your local parts counter
1 set of bumper turn signal lights with harness ~$35 for set of clear ones at autodynamic.com
1 set of ugly orange vent thingys (if you wish- i dont have any bc they dont do jack)
1 bumper beam; 3 options. Sti lightweight bumper beam $58 @subaruparts.com, OEM 2001 RS beam ~$110 @ parts counter and 25 lbs heavier, stock L bumper beam + grinder and saw = $0. stock L beam in unmodified form will NOT fit. sorry. foam thing will be thrown away as well, dont ask me what it is, you'll see it when you take bumper off
this having been said, all that is required is to remove the bumper beam - 4 17mm bolts, remove the random small 10mm bolts that hold the bumper skin in place, and the fixament thingys that hold the ends of the skin in place by the wheel wells. i dont remembber how it is in place OEM, i have a special way i do it myself.
reuse the metal top arch piece that sandwiches the bumper skin, and re-install the new parts jsut like you took apart the old parts. hoooray. you look cool now. the turn signals will plug right in, exact same harness ends, jsut differnt bulbb setups.
hood/ lights / grille conversion:
97-01 hood and lights and grill are all the same shape.
differances in lights:
93-96 is fuzzy lense and rounded
97/98 is fuzzy angular
99-01 is clear angular. these are hott and hard to find. i dont have any for sale.
93-96; rounded and fits the lights
97/98: angular, i believe its = STi v4 iirc
99-01; usdm market is same as 97/98 iirc
93-96: usdm rounded steel sans hood scoop or vents
93-96: JDM STi version 1-3 one is aluminum, has thin scoop and floppy vents. $$$$ to find one. weight is about the same as STi version 4-6. (i have both- NOT for sale)
97-98: usdm steel, angular front, no scoop heavy
98-01: usdm 2.5 RS / obs steel. looks cool and has proper vents to fit STI aluminum hood, just heavy
JDM STI v4-6: aluminum lightweight hood, vents and scoop compatible with all usdm OBS/RS parts.
sti v1-3 had all rounded hood and bumper, sti v4 had angular hood and rounded bumper, sti v5-6 had angular hood and angular bumper. i thinks.
fenders: all fenders are the same. jdm had no moulding on lots, you can shave the moulding or buy a 98-01 RS fender that has no moulding factory stock.
headlights / grilles / hoods fitament:
angular grille will NOT fit with rounded headlights.
angular headlights WILL fit rounded grille
either hood will fit with either headlights.
to do conversion ala my personal green bus,
sti v6 aluminum hood ($454)
2001 RS headlights $180 (used)
1999 RS grill piece ($35 used)
2000 RS hood scoops adn vent. ($120 used)
2001 RS bumper ($220 new)
clear turn signals ($35 new)
sti bumper beam ($58 new)
$1102. + paint, labbor, whatnot.