[Blue Tank]

I've been learning about this over the past couple of days myself and hope to wrap it today. I stayed with r12 because of the T fittings to the rear.
My rear unit would blow real cold while the front would be cool. I bought the poa replacement valve and a new Expansion valve along with new lines. The big flex line isn't bent exactly the same from the rear of the POA so the heater hose doesn't fit in between it as good. You better be in a real good mood before you try to get that 3 piece line kit to fit. The grommets that comes with the line kit don't have separate holes for the lines to keep them from rubbing, i reused the old one. I took the center grill support out which lets the grill drop enough so you can change the hard lines.
The new large lines slipped over the t fitting with oil easily, the small ones stopped right after the ridges and wouldn't budge. I bought the hose clamps with the extra strip in them so they don't dig into the hose.