ac not blowing cold. or even cool.

[dusterbd13]

so i have built a system for my 64 el camino.
parts:
66 vintage mark iv monitor underdash unit
new expansion valve
r134 barrier hoses, all o-ring fittings except the two flare fittings for the underdash unit
new parallel flow condenser, as big as the radiator
new drier
vintage air manifold for Harrison r-4 compressor
used 89 vintage Harrison r-4 compressor, complete with the rest of the serpentine accessories (from extended cab fullsize truck)

the system was built by me, and initially charged with PAG oil and r134a straight out of the can. no vacuum applied. I never got the pressures up to where the gauge on the can dispenser said it should be, but the system was blowing about 10 degrees below ambient temperature inside the cab.
I then took it to a local shop for a line flush, proper oil, vacuuming, and correct r134 charge. it reads within spec on the gauges according to the shop, but blows ambient temp. the low side fitting coming out of the evaporator is cool to the touch, but not very. no condensation being formed. this is regardless of engine or vehicle speed, so I doubt its airflow related.
engine has a mechanical clutch fan.

what are my options here? did I miss something in system design? did they miss something with system pressures? anything I can do to make it work better? am I expecting too much?

thanks guys. usually I install aftermarket streetrod kits and sanden compressors, but wanted to do something different (and cheaper) this time. hoping im not going to regret this.

[minendrews68]

I would break the system at the expansion valve and look at it to see if it was clogged up. Also look at blowing the system, just take it loose at the compressor and have your compressed air blow away from the compressor on both sides.This could happen if there was any trash in the system prior to buttoning it up. This could happen even in a new system. If that isn't it I would take it to a reputable auto mechanic or a radiator shop that does automotive ac. Hope this helps some..

[sccacuda]

What are the high and low side pressures when the system is running?