GMC Sierra 1500 Bed Size for Overlanding: Short Bed vs Long Bed, From Someone Who Actually Had to Choose When I was configuring my 2025 Sierra 1500, the bed length question wasn’t academic. I had a king-size rooftop tent, a dual-zone fridge, a full rack system, and a family of five that all had to fit into one truck. The bed length decision felt like it had a wrong answer. Pick the short bed and you’re fighting for space. Pick the long bed and you’re fighting for parking spots