I just used a superchip tuner on my '99 5.4, 4x4, 4.10 gear, super duty. I set it for the raised tranny shift points and performance mode. The trans. shifts really hard now . I guess that's the idea, but will it be harmful to the trans/driveline in any way? My truck has 227K miles on it. I just don't want to cause a problem by using this setting. thanks

 

Those hard shifts are only good for one thing - cooler transmission temps when being pushed hard. But the shock it is putting through the gearsets and the rest of the driveline will ultimately cause damage or at least, accelerated wear...
Pick a lower tune for the transmission like a towing tune. Firm shifts are good for towing - hard shifts are not...