while the rack itself is NOT GM but that of TRW and also USED on the 4200 lb series of Chrysler LHS. The inner bushings and such is the same both applications. You got to keep in mind that these aftermarket companies has to default to the rating of the supplied donor part for liability purposes. Take it from there.....to say there are no rack and pinion units for a vehicle over 3500 lbs is ludicrous. The Dodge Sprinter is the first to pop into my mind....not to mention the many trucks up to 3500 (Curb weight: 6,956 lbs. Maximum towing capacity: 34,110 lbs. Maximum payload: 4,440 lbs. Gross weight: 11,400 lbs)
the light weight 6000lb car frame will fail first.