Demon's in my engine or tranny?

[96rangerdanger]

So, I have a 96' ranger 2wd 5spd. I replaced the clutch and slave with a factory setup, and did the valve cover gasket. My truck was down for about a month or so. My fuel pump was whinning when I first started it. And now when I'm driving on the freeway, it cuts in and out. Probley the fuel pump. Then on top of that, my truck should be at 80MPH in 5th gear and 3000RPM's. Now since I changed the clutch and valve cover gasket, at 3000RPM's I'm doing 75 MPH. WTF? My clutch does not slip at all. Not even off the line. NO ONE has been able to figure this out. I asked people at a transmission shop and they had no idea. Can anyone explain this?

 

[steve63]

is the truck throwing up any trouble codes?,whens the last time u changed the fuel filter?

 

[96rangerdanger]

NO codes at all, and I changed the fuel filter about 4 months ago with a filter from kragen auto.

 

[envious8420]

this is most likely the fuel pump as well, not supplying enough volume at wot.
a good rule of thumb is 8oz. in 15 seconds. pressure might be correct but it also needs the volume to run at speed or under a load.