1964-1966 center a/c vent

[wahl4m]

i never had a factory air unit in any of my trucks working ? im wondering if the side vents you are doing -really help w/more air ? i just never could imagine the stock vents being enought for a crew cab or carryall ? anybody have any ideas ? also with the 134a - is it cooler than the r 12 ?? im sure the r-12 is very expensive & impossible to find ? not trying to hijack your site -just thought somebody here might know ?? im sure i will sign up for some side vents ?? thanks mike{now i need to practice my "fawn " painting skills -your pics look great !!}