I have a 99 Tahoe Z71 powered by a LT1/340hp V8 (Yes, its original). Rear axle seals have always been a problem. Finally had to replace the axles. Brakes a huge problem; finally replaced with "greenstuff brakes", the jury is still out on that verdict. Transmission and engine still real strong after 121k miles. It's all the small stuff; power steering pump, alternator, fuel pump. However, try to tow 8000 pounds with your Toyota over the PA mountains! Gas mileage is 14/17. I can only use super unleaded fuel. I had to replace the entire exhaust system because both cats went out at 90k miles. Absolutely crazy; cats usually outlast the vehicle.
340 horsepower; the heated seats are like volcano strength; with fuel flowmaster exhaust and K&N FIPK, the engine really roars.
BRAKES! Try something else. Supercharge the engine.