Hey guys im new on here i need help

[75sierra]

So i have a 75 sierra grande 4x4 and im having an issue and i'm stumped! My truck starts right up and shifts into gear no prob but i can only take off real slow if i punch it the motor revs but it doesnt go i checked the kickdown cable but its tought. Any suggestions?

[thirsty]

Is your tranny slipping?

[75sierra]

No i dont think so its really strange its hard to tell because u have to ease into the throttle so much. Im thinking torque converter?

75 sierra grande

[beastie_3]

low fluid level too

[bake74]

     First off welcome to the site.  So you said you checked the kick down cable and it is "tight".  Silly  questions here, have you checked your transmission fluid ?  Are you sure your not in 4 low ?
     After those 2, I would have someone drive your truck, lay next to it so you can see the rear driveline, (not under it of course), have them take off like you described.  If your rear drive line is spinning slow even though the engine is revving high, then transmission or transfer case is problem, if the rear driveshaft is spinning fast, then you have a problem in the rear end.
      Try these and report back unless others can chime in and tell you what it is.