93 Silverado Z-71 with very high mileage and its third transmission. My 17-year-old drove it approximately 1-mile on a 4 degree morning, and it ran fine. It sat two hours and now the RPM's won't go above 4000 and the truck won't move in reverse. I drove the truck home and had to hold it to the floor to climb the mildest grade. Even when in PARK while reving the engine it seems there is a great load on the engine, but there is no misfiring. Timing is fine. Could this be a Torque Converter problem?

Gotta have this thing running! Too many kids going in Too many directions...