Noob need hlp with home ac

[selkov]

Just bought a new home.
I am unhappy with the A/C system.
The A/C contactor that installed it is of no help.

I would like two things:
1] If it is not against the forums rules...Recommendations
For a honest Local Tech That KNOWS what he is doing in
the Jacksonville Fl area to do a Manual J as well as to
Checkout the systems performance & wiring

2] Confirmation that I an not crazy...
The home is 3200Sq, two story. Uptairs is a 3.5 ton Lennoz 12 seer zonned to the upstairs & downstairs bedrooms. The rest of the house downstairs is on a 2.5 ton lennox 12 seer.

Outside temp all this week has been a high of 92-94, low of 84-86. The downstairs unit runs from 9 am to 11 pm nonstop and can NOT maintain 77. In fact it will go as high as 81.
The humidity sensor reads high of 55 lo of 46. If I run it alone or along with the upstairs sytem this does not change.

It is not so much that it is costing me ALOT of $ to run this but that we are uncomfortable and doing so.

I have some basic A/C skills and as such am sure that there are no leaks in the duct work (but not if they are the right size), filters are new, evap & cond coils clean and unobstructed.

Also I have hard specs on the system:
Low side PSI = 69 Line temp* = 64 Chart Temp = 40.5
High side PSI= 265 Line temp* = 93 Chart Temp = 121
*Temp was optained using Infrared Thermometer
Outside temp was 90
Inside temp was 78
Temp differential at airhandler 20.5

I welcome anyone who can offer suggestions to do so.
thank you.