I have a 00 sierra with a 4.8 and 119,000 miles on it, and I have piston slap to the max, especially on cold mornings. Sounds like a diesel and fades to almost quiet after maybe a minute. Every day is slightly different. The auto trans is getting weird sometimes and the rear end won't unlock sometimes. I bought the truck with 67,000 and change oil religiously. Now the oil level light comes on before the next oil change and where I need to put in the full dipstick worth of oil in to bring it up. It is not leaking and I see no smoke. The engine is getting noticably weak and ? Of coarse the fuel float in the tank is bad also. Geese! 119,000 miles and this truck is wore out. Should I dump the truck and pay 14 - 17 grand for a good stock replacement, or put that amount into the truck. I just cannot in good conscience sell this truck to an unsuspecting buyer with a bad engine.

Need Engine
trans
Rear diff
fuel tank float
Just overhauled the brakes on all fours and body is reasonable

Anyway, I need another motor to start with. What is needed to be changed or converted to put the 5.3 into the 4.8 truck. ecu, engine electrics, hookups, trans, motor mounts or anything else.

I found a 04 SILVERADO REAR DIFF, REAR DISC 4X2 3.08 RATIO for $400 from a private seller. Is that a good or proper diff.

I don't know much about these trucks yet, but learning. What is the best diff to install and how do I identify it.

Your opinions would be appreciated

 

Check your fuel pressure, my Burb got real weak and it was not getting enough fuel. After that the engine lasted until 223k