3.1L V6 Coolant Capacity

Can anyone tell me what the coolant capacity is for a 3.1L V6 is? I don't have an owners manual, I can't find it in Haynes repair manual and I can't find it here on the wonderful internet. I need to flush and change the anti-freeze in my '92 Lumina and need to know. Any tips or advice on doing it would be helpful also. I'm having a heating problem and I put in a new thermostat which didn't solve the problem but did discover that the anti-freeze looks BAD. Thick and brown. From what I've read here in this forum it's looking like the problem is pointing to the heater core being the culprit. Does it make sense to try the flush and change first to see what happens? I'm new here. Thanks for any help or advice.

Add 1 1/2 gallons of antifreeze, and fill the rest of the way with water for a 50/50 mix. The heater core won't usually cause an overheat problem, if it's bad you'll have no heat. I recommend buying a flush kit at any parts store. It has a fitting allowing you to hook up a waterhose and flush the cooling system properly.

Here's a website to help you drain, flush, fill and bleed your cooling system...

http://www.autozone.com/servlet/UiBroker?ForwardPage=/az/cds/en_us/0900823d/80/0e/c4/d4/0900823d800ec4d4.jsp#hd1-1-5

Checked out the website you recommended for some pointers. I took care of the 'no heat' problem by back flushing the heater core (easy!). Then did a complete drain and flush of the entire system. I also used Prestone Super Flush. Put in some new anti-freeze and BAM.... now the heater blows the doors off!