Would the rear expansion valve contribute to the fronts preformance? I plan on changing both to be safe. Should I consider a parallel flow condenser? I hear they have better cooling preformance. Just wanted to get a few opinions if anyone has any knowledge on those.

 

Rear expansion valve has no bearing on the front performance but the front valve may be restrictive
A stock condenser should perform well if its healthy. I wouldnt try to modify the system as a band aid to compensate for other defective partts

 

Just come back to this post to gain more knowledge.

Quick note- yesterday while idling my high side lines were extremely hot, while the low side lines had almost no condensation on them. The line was slightly cool but not ice cold. Seems like the system will cool sometimes, then not cool at idle. What could this be an indicator of?

How do I test my thermal expansion valve? As of now I'm thinking this is the only thing keeping my system from blowing ice cold air. Today was 91°F and my front vent Temps were 68° F while traveling 75mph, max blower settings. Since I already have a completely brand new system, ( compressor, evap core, ac dryer, fan clutch) what else should I do? New xpansion valve to be safe? Then have dobbs charge it the professional way?

I seen a post recently about 3500 vans, and that temp sensor that pokes into the evap core. Trying to understand it but not sure if that's an issue, since before I replaced all these parts it blew pretty cold, evap was clogged and didn't have air flow. New evap in, great airflow just not so cold air coming out. Thank you all for the tips and knowledge.