has anyone tried any performance up grade and if so what was your results?

 

What are you going to run the tuner on? 7.3, 6.0, 5.4, 6.8?

 

it's a 2003 f250 6.0

 

My 05 6.0 has been running a Diablo Predator, 65HP setting for the last 20K or so.. No problems.. 'Most' times I behave, but well, sometimes I can't Even at that setting the power gain is pretty impressive.. I don't run in the 100HP setting because I don't think the 6.0 will take a pounding to that degree for too long.. My opinion.....