My dad has a 01 or 02(i dont remember) silveardo 3500 with a 8.1L and he needs to replace the camshaft positioning sensor.. We cant find it though.. Where is it?!

 

If its the same as my 5.3 its behind the intake manifold in the block on the passenger side. There are 2 pligins one is round(not the one)side by side and the others oval like a 3 or 4 pin connector. Take the connector off and take out the bolt on the left side and rotate the sensor back and forth to loosen. Then you will have to muscle it twisting and pulling to get it out as its tight and a real bitch

 

It's the short one on the left, in the center of the block.