What should you check before buying a used 7.3 Power Stroke?

Start with the truck, not the reputation. The 7.3 Power Stroke has a strong name, but these trucks are old now. Check cold start behavior, glow plug system, batteries, cables, fuel bowl leaks, oil leaks, high-pressure oil system leaks, valve cover harness issues, turbo boots, blow-by, coolant condition, and exhaust smoke. Listen for rough idle and watch how it starts after sitting. Then inspect the chassis. Rust, worn steering, tired suspension, brakes, tires, bed mounts, cab mounts, and transmission behavior matter as much as the engine. If it is an automatic, make sure it shifts cleanly under load. Ask for service records and look for evidence of hard towing, tuning, or neglected maintenance. A clean 7.3 can be a good buy. A rusty or abused one can still cost a lot, even if the engine runs.