I installed a 2001 5.3 rebuild engine on my 2011 gmc sierra 5.3. Original 2011 intake worked on new engine but now I have problem with the crankshaft sensor. And it won’t start even after replacing the sensor. Any suggestions?

 

That's because the older engine is a Gen III LS-based engine and the crank has a 24x reluctor wheel.

Your 2011 is a Gen IV LS-based engine and has a 58X reluctor wheel.

There's a gadget that converts 58X to 24X, but I'm not aware of anything that works in reverse...

Best bet is another engine that's a Gen IV so everything matches.

 

You need to physically replace the crank reluctor wheel. Engine needs to come out and you either need a 58x crank reluctor wheel or you need a different crank.

 

Plus he needs a 4x 3 bolt camshaft gear if he does the reluctor swap.

 

@FFDP I purposefully omitted that.
He is going to have issues with knock sensors too.

 

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Yes. You have a problem.
The simple, and cheapest solution is to install your new "rebuld engine" in a 2001 truck.

 

Unfortunately this is all too true.

While "possible" to adapt that motor to your truck, there are too many little detail differences to overcome, to make it worthwhile, in most cases. The crank sensor compatibility issue for example requires COMLPLETELY removing the crankshaft from the engine. It's gonna cost you more money, time, trouble, and risk to do all the things that are needed, than just selling it and getting the right thing that fits your truck.