98 chevy c/k2500 clutch - 1998 Chevrolet C2500

SOURCE: 1999 k2500 4x4 5 speed started grinding only when

If it is noisy only in third, then third is where the problem is, cluster gear and/or mainshaft gear. Rule of thumb, if it is noisy in only one forward gear, then that gear is where the problem is.

SOURCE: 98 chevy sub. k2500 to accelerate poorly

Likely a clogged fuel filter or defective fuel pump. Confirm correct fuel pressure with a gauge. If the pressure is low, remove the fuel filter and check for obstruction. If it's hard to blow through it, replace it with a new filter. Then retest the fuel pressure. If pressure is still low, then it's likely that you have a defective fuel pump.