Here's what's involved in the install for a vintage air system. It ended up costing me about $1,500, ($1150 for system, $70 for system charge, $200 new 4 core radiator, $60 to rebuild A/C controller.)
http://www.67-72chevytrucks.com/vboa...d.php?t=249479
It'll freeze you in the middle of summer. Mine worked well in even 110 degree carolina weather.