I know the motor will fit, but is all the electrical the same? Its a 5.9l coming from a 1999 going to a 2001 with a 5.9, I just want to know if its identical, or are the harnesses different.

 

The engine in my 99 came from an 01. The only thing different was the oil pressure sending unit plug. I changed out the sending unit and everything worked perfectly. I was told that this is not always the case and that usually it never happens.

 

you should be o.k., but if you have emissions testing in your area and a strict enforcer, they will notice an older engine in a newer pickup. That's an automatic fail.

 

yes they should be the same, i would keep your intake manifold though just in case. and no one will be able to tell, they were exactly the same casting.