i WAS WONDERING which is better to use?

 

Neither one of them belong on a truck, due to the weight and nature of the vehicle. But if you're asking which is safer, then I'd have to say the spacer...as long as it's not too thick.

 

This guy I work with had some adapters on his pathfinder to fit some 20" rims. As he was driving the driverside front adapter decided to snap off. Needless to say the wheel flew off tearing his fender up. Then rolled and hit a curb, went about 25' in the air and landed on a parked car at a gas station. He now is a insurance nightmare. I say stay away from both!