I can't speak to the 240's as I don't have one any more. Whether the system can put out these temps with 134 may or may not work. Unfortunately the only way I can think of would be to increase the size of the evap and condenser which would be a challenge.
As to the NY temps today it was 97* when I got off of the golf course at 2 so I don't know where your brother lives but I would like that temp here.

 

we had a cold front come in 70s at night and 90s during the day. Thought I was gonna have to get my winter jacket out. LOL. Im thinnking about doing a Evap. and fan change in near future. Thought about changing to an aftermarket setup. But? Will be alot of fabing.

 

Getting 38 degrees on a probe is easy. You turn the fan to the lowest speed and measure the air temperature. Most all systems should yield a reading like that on low fan speed.

The problem with the 240 is simply that the system is not large enough to handle the high heat and humidity of a hot southern US climate. The system was resized in 1991 and those are much better systems. For 1993 they are R134a with a booster fan and work quite well.

The only way to get an early 240 to produce good air conditioning is to either run it for 30 minutes at highway speeds to cool down the cabin over time or to upsize the components. I am not sure if the retrofit kit to upsize is available anymore.

 

Can't speak to the 240 as I don't know about the AC system setup. I know that when we bought new the 740 the AC blew cold without any problems and the cabin was cold enough that all you needed was the low speed fan. Our summer temps in our area usually runs from 75* to 95* with a few 100* burners once in a while. The Volvo 134 kit was just a receiver/dryer , orifice valve , o-rings and compressor oil. The 134 was not as cold but the outlaw of r12 convinced me to do the change. The only way I think to make it better is with a larger evaporator and condenser. So our 740 AC runs cold and most of the time I don't exceed more then the 2nd blower speed. Works for me.

 

Cooled down today to 94* but it still wasn't pleasant cutting the back acre. Somehow I think you would have a difficult time fitting a larger evaporator in your car with the location of where it is. You may want to document it for others if they want to do it.

 

Well, I have a 1992 as a donor, but I would rather not change the condenser. Thankfully, other than lately, it doesn't usually get oppressively hot here in the North East.

 

Condenser is pretty easy as it only requires pulling the grill and removing it from the radiator brackets. The evaporator in the car is the tough one as you need to remove most of the dash to get it out.

 

If you are going to change the condenser, you will need that booster fan and associated electronics. Without proper airflow, it won't cool any better.

 

how hard or is it possible to clean the evaporator on a 240? Know its alot of work to replace but with it being over 25 yrs. Im sure a good cleaning would help it.

 

Are you referring to flushing the component or cleaning the outside?

 

The evaporator in the R12 car just has hoses going into the evaporator, the 134a set up on my donor car has hard lines going into the passenger compartment, circled in yellow, so I assume if I were to change to the 134a dryer I would have to swap out the evaporator under the dash?

 

You do not have to change the evaporator. They make a flush kit to just flush it out. The reason is to get out any oil from the R12 compressor. Same with the compressor where all you need to do is flush it out and empty all of the oil in it.