95 ford f150 4.9 inline six

my 95 ford has this problem i cant figure out it die in nuetral when i shake my drive shaft and when i do 60 mph it starts to hickup really bad so i cant go abouve 60. i have replaves the u joints checked the rear end brand new clutch and it still does it any ideas what it is?

Change the fuel filter…

i have already replaced that

This is a real wild guess but it might apply. Check the ground cable to the engine and the ground strap from the engine to the chassis. I am wondering if the engine is trying to find a ground through the drive shaft.

Give us the answer if you ever find what causes this.