are we talking about water radiator or ac condenser
A lot of Freon R12 systems were undersized in the first place and are inadequate for 134
So measure carefully and find the largest condenser that will fit if you are going to all the trouble to convert
plug all the holes in your core support
run a spoiler/ valance
obviously a shroud
and a thermostatically controlled fan with lots of blades
I run 9 but I'm Magnum reverse/ serpentine rotation
new GM reverse is 11 blades
more blades with less pitch is quieter
on MY 92 Dakota there is a service bulletin which raised the thermostat fan by 10 degrees and went from 7 blades 3" pitch to my current 9 at 2.5 inch pitch
BIG DIFFERENCE
forget flex fans etc
Now some news from the past
first year of 134 Ford made no changes- lots of complaints so with a service bulletin and for the next year they added an electric fan (a puller hidden in the shroud)
and made the HD Police Taxi/ trailer tow cooling available to more geographical areas standard
no factory spends these kinds of bucks without a very good reason
We did tests for Ma Mopar on the famous "Baker Grade" out by Death Valley
Ma was having overheating in slow speed stop and go driving up hills- like when there was an accident.
Turns out that the tail wind was faster than the vehicle and recycling hot air from under the vehicle up and back around through the radiators.
Fix was valances/ spoilers
even a small one helps
Fun Times