86 silverado air cond upgrade.

[ozkiwi]

I am moving to a much hotter climate and the stock air cond in my truck has never been that great.
It has a new four seasons compressor.
New dryer.
Shut of tap for the heater.
Re gased.
When engaged it sends a vibration through the truck at idle even with the solenoid idle kicker is engaged. Not sure if this normal as it did that with the old pump as well and I thought the new one would eliminate that?
It also kills my gas mileage by way more than I would expect but maybe that's normal also?

Is there a more efficient modern compressor or complete set up I can install ?