If you look carefully under the hood you will find a sticker that will give you the poundage. Some systems still have what is called a "sight glass" that is usually located on top of the receiver dryer. what the sight glass does is let you know when the system is full. (when the system is slightly low you will see a white foam in the glass,when full no foam)
The 2004 Jeep Grand-Cherokee has an inline 6 engine.
The 2004 Jeep Grand-Cherokee has a 4.0 L base engine size.
The 2004 Jeep Grand-Cherokee's engine produces 195 hp @ 4600 rpm.
The 2004 Jeep Grand-Cherokee's engine produces 230 ft-lbs. @ 3000 rpm.
The 2004 Grand Cherokee has options for a 4.0L inline 6 and a 4.7L V8.
A seat from a 1999-2004 Grand Cherokee is what fits in a 1999-2004 Grand Cherokee.
2004 was the last year for grand cherokee's and 2006 was the last year for the wrangler to have an inline 6
The 2004 Jeep Grand-Cherokee has 12 valves.
The 2004 Jeep Grand-Cherokee has overhead valves (OHV).
The 2004 Jeep Grand-Cherokee is a gas-powered vehicle.
The 2004 Jeep Grand-Cherokee has a 4-speed automatic.
If it is the 4.0 engine. then it is a different part number. If you could give what engine you have it would help to let you know.