Head swap

[chogeberg]

Can I put heads from a 2001 onto a 1994. What do I need to do if anything to use a 2001 engine in a 1994.

 

[stmitch]

The heads are the same.
To put the 01 engine in your 94, use the long block, but keep your intake manifolds, and all electronics. Basically the block, pan, and heads are interchangeable.

 

[chogeberg]

Do I need to change the harmonic ballancer or can I use the one from the 2001 for the long block?

 

[stmitch]

The balancer should be the same

 

[chogeberg]

Could I get an ecu and use the 2001 as is. I already have the harness

 

[adsm08]

You would need the dash wiring as well.

 

[stmitch]

As ADSM said, you'd need the cab wiring harness, but essentially, all of the wiring on the truck would have to be swapped out.
Your 94 also has a return style fuel system, and the 01 used a returnless fuel system, so that would have to be switched out too.
It's really not worth switching out the entire electrical and fuel systems to put another 3.0 in.