My truck is a standard and it won't go over 1500 rpm before it makes me change...

[Pedal2TheMetal45]

HI
sounds like your having timing problems.. or its not getting fuel.. if it just bogs down I'd think on the not getting fuel ... if it miss and back fires then I'd say timing..
good luck
tim

 

[TOMMYD]

...gears. Top speed is 45 mph? If I try to push the gas after 45 mhp it bogs down and slows down.

 

[bandit_60]

sounds like the clutch is slipping.