Can you put a 5.9L cummins in 96 F150?

No, you can't easily put a 5.9L Cummins into a 1996 Ford F-150. The frame, suspension, and engine bay of the F-150 are simply not designed to accommodate an engine of that size and weight. It would require an extensive and incredibly complex (and likely prohibitively expensive) custom fabrication project, involving significant modifications to virtually every aspect of the truck's structure. It's far beyond a simple engine swap.