My truck runs and idles fine until im going around 50 mph and holding around 1100 to 1200 rpm, then the truck starts to studder like its misfiring or losing power, no check engine lights or alarms, oil level is fine, new timing chain and tensioners installed less than 20,000 miles, the truck has always had this problem and i dont know how to fix it

 

There are many problems that will not set off the check engine lamp.
One of which is a restricted fuel filter.
At higher RPM there us an increase in fuel demand. If the pump or filter can't satisfy that demand, desired response is limited.

When was it last changed?