I've still got 2 Duralast's that came in my '82 K2500 when I bought it,one was a "gold" and the other the basic black one--both looked old THEN,and that was 2003!--I have let the truck sit months at a time,yet it starts nearly every time,its only when its been 20 degrees it didn't want to fire up last winter gue to glow plug problems..
I've had a few red top Duralasts go south on my fairly quick though,but I did buy them used from a boneyard--they were less than a year old though when I got them--got maybe 2 years out of both of them,they came from a GM diesel pickup..
My '85 Suburban has 2 big "Continental" batteries in it that look old too,think they are group 27's,top post..that thing has sat in my yard alomst 2 years and I do start it weekly or at least a few times a month,and it often refuses to start and I drag them down--but they always recharge quickly and will crank the thing over a good while until it starts...till I got them I never heard of Continental batteries..
Some guys who plow commercially here buy group 31 batteries if they will fit in the stock battery tray,they seem to hold up better than regular passenger car batteries..they have a lot of plates and withstand deep discharge and uses like winches and a lot of additional lights..
I'm not sold on any "spiral cell" batteries like an Optima or any other hi-tech gee whiz ones..most of the ones friends bought were a huge dissapointment as far as retaining a charge if you let them sit more than a few days..I think getting a battery thats got enough capacity is more important than name brands,one with more plates always last longest and performs best..