You do realize that the transmissions in grand prixs are ultra weak sauce
the grand prix isn't in the same class of car as a corvette. a vette should have a great tranny not a crappy one. the message here in this thread are that c4's are crap
2005 Grand Prix GT - Corsa Sport Catback, Thrasher Shift Kit, Custom Open Cone Intake, Spyder Chrome CCFL Halo Projector Headlights, CG LED Tail Lights, Pioneer DEH-33HD stereo unit, Alpine SPR-60C 2 way 6 1/2's, Kicker KS 6x9's