im not sure about your vehicle but you may be able to make pedal adjustment under the dash also if it is fully hyadraulic it has a slave cylinder either in the bellhousing or just rightoutside the bellhousing it might be adjustable somewhat but they usually have to be replaced is your clutch staying engaged while you have the pedal pushed in if so more than likley the release bearing(throwout bearing)or the slave cylinder is out if it has one not sure about your truck.
brad