Here's the specs from the FSM...
Part Number - BCI Group Size Classification - Cold Cranking Amperage - Reserve Capacity - Ampere-Hours - Load Test Amperage
56027960 --- 34 -------------------------- 500 -------------------- 110 Minutes ------ 60 ------------ 250
56041003 --- 34 -------------------------- 600 -------------------- 120 Minutes ------ 66 ------------ 300
I have a spiral cell batt from work, 6 years old already but was one of four being scrapped due to constant jump starting of the kit. My old battery was getting weak so I charged one of the four up and tested it, it's healthy and it'll kick out 1000A according to the digital batt tester (Batt rated at 950). Nice for free! The others all tested OK too and went to good homes.