* The vehicle's owner's manual: This is the most reliable source.
* A 1987 GMC Safari brochure or specification sheet: These often list curb weights for different models. You can try searching online for these documents.
* An online vehicle database: Some websites specializing in vehicle specifications might have this information, though accuracy can vary.
Without knowing the specific trim and options of the 1987 GMC Safari, it's impossible to give a precise curb weight.