I swapped out my 1.3 for a 1.6 and was looking to change out the 1.3 radiator for the 1.6 also.  I was looking at it and it looks like it will fit if I make new mounts and modify my hood.  Or is any of this neccessary,  Maybe I should just stay with the stock rad.  Any suggestions on what I should do.  I also have an electric fan that I am going to install.

 

If I remember correctly when Petroworks swapped in my 1.6 16v they replace the core of the factory radiator but they keep the stock top and bottom. I would give them a call and see if they will just sell the radiator to you.
My 1.6 16v runs really cool.

My 1.6 8v usually ran cool.  I removed the motor fan and only used the electric fan when on the trail (even forgot it a couple times there too).  Any radiator shop could recore your radiator if that is the what is needed.  I would try your present radiator first.  Just let it idle and see if it overheats.  That has the least airflow through the radiator, and will let you know if it has the capacity for normal use.  Rock climbing in Moab, Johnsons Valley, ect may require more cooling.