Well for a Bonneville some of these parts won't work, but for a GTP this is what I would do for $1000:
3.4" Pulley $66, maybe a modular pulley system if I knew I would do mods later ($150)
1.9 Rockers - $300
DHP PCM - $300
ZZP Ported Exhaust Manifolds - $250
U-Bend Replaced w/Straight Pipe - ~$40 at local exhaust shop
Drilled 180* Thermostat - $10
AC-Delco 41-919 Plugs - $25
Grand Total: $991, $1075 with the modular pulley system
Thats what I would do....those mods would significantly wake up a GTP (60+hp), and with another $100 invested in a Mini-AFC and a modular pulley system and a $35 K&N filter put on the intake, you could mostlikely tune a car with those mods to run a 3.3" pulley. (you have to remember a GTP gets less KR than a SSEi because there is less load on the engine because it doesn't have to pull as much weight)
1990 Maroon Grand Prix STE McLaren 3.1 Intercooled Turbo, 14.695 @ 94.49 on 12psi before cam/heads/etc.
1990 Bright Red Grand Prix McLaren 3.1 Intercooled Turbo, 14.819 @ 92.72, 189whp
1999 Grand Prix GT 9.75:1|K&N|160 tstat|No Ubend/Cat/Res|UD Pulleys|Ported M90/TB/Heads|XPZ|2.55"|Pacesetters|Stage 2 I/C. 12.442 @ 112.78
2000 Blue Bonneville SSEi Supercharged Gutted Airbox|K&N|3.4"|1.9'*|WP Pulley|Custom DHP|180*stat|41932'*|No Cat. 14.681 @ 94.80
2002 Dark Cherry Grand Prix GTP Supercharged & Intercooled
12.084 @ 114.38 w/1.743 60', 315.6whp, Fastest Stock Cam M90 GTP!
NOW XP CAMMED, 340.6whp with XP, stock heads, Gen 3 M90, 11.984 @ 115.84 w/1.750 60'!
Most HP Stock Heads Gen 3 M90 GTP!
2004 Red Monte SS Supercharged K&N|3.4 Pulley|1.9'*|180*stat|41919 plugs|3" dp|No cat/ubend|DHP|Shift Kit. 14.2 @ 98
GOT BOOST??? Friends dont let friends drive stock!