Hi Davey,
I would say yes with no hesitation. You will get a much better control of the cooling temperature in any conditions.
And you can get rid of the ugly original plastic fan from the Pinto, which is a must
I have a Mercedes 190 radiator, and I fitted a 12'' fan. There was an electric fan control on my engine (2.0i DOHC), so I reused the wiring and it works perfectly.
For your Pinto, you will have to add an auto fan switch.
Some pictures of mine:
2013-06-07_14-34-09 par
Voucht71, sur Flickr
2013-07-08_12-02-25 par
Voucht71, sur Flickr
Good luck
