sounds like your fans are not coming on check your fuses under the dash on drivers side and your relay located under the hood near the batery

you should replace your water pump with a metal impeler water pump, the plastic ones are known to come a part

98 svt sil/blu 3.0 oval heads full P&P, msds headers,bat kit,2,1/2exhaust 30 inch glasspack and 2 spintech mufflers 14.78@94mph with my mechanical arm i can shift gears in less then a twentieth of a second for sale $7000