Ditto for our '06 Monterey as what Craig reports. Reserve capacity 195 minutes at 25 amps at 80 degrees F. That and the 950 CCA are the minimum; larger specs are acceptable.
Our original batteries are still good, but in checking my stats for you, I see we have a 140 amp alternator where I thought it was a 160. All the more reason to make sure you use the genset to recharge things before leaving a dry camp; driving off and overtaxing the alternator following an extended dry camp is the fastest way to ruin it.
Joel