I own a 92 5.0 equipped with a Tremec TKO 500 transmission. I also have a centerforce dual friction clutch. For some reason it is really hard to shift gears. It will upshift into 3rd, but it wont downshift into 3rd gear. I tried adjusting the clutch cable, but it's only worse. Now 1st and second gear are hard to shift into. My tranny fliud is at proper level and was just changed three months ago. Also my shifter vibrates if I go over 75mph even out of gear. Somebody help me out here.[&:]

 

was your flywheel resurfaced when you put on the new clutch? also it could be your drive shaft causing the shaking above 75. i had that problem before. anything over 70 and everything shook. lastly if your clutch wasn't torqued properly it may cause this also. i'd keep checking your clutch cable and then narrow it down from there. hope this helps.