Tell me a little more about the 6.2/6.5 engine, what's 6.2 and what's 6.5.
I'm guessing that the cracks that you found were the short cracks that appear between the valves, but none elsewhere?
Most of the cracks between the valves are surface in nature and usually don't leak, but that's where the K-line liners are for. They should be thin in nature, to maintain a flow of coolant through the passage.
Which cylinder is leaking, are you bleeding compression presure into the cooling system or are you getting coolant into the cylinder causing a hydrolock situation?
What clues were visually there to determine that the cracked head was the source of coolant into the cylinder?
J
1982 C10 SCSWB 6.5TD, mods too extensive to list. (13.69 1/4 mile @94.6 MPH) RACE TRUCK
1982 C10 SCSWB 6.2NA, 2.73 700
1986 C10 SCLWB 6.2TD 3.73 700
1989 V20 SUB 6.2NA, 3.73 400
1994 G20 VAN 6.5NA, 3.42 60E
1994 K20LD ECSWB 6.5TD, 3.42 80E
1995 K20 SUB 6.5TD, Wrecked, ran into by stupid teen.
1995 C3500HD DRW 6.5TD, 12' Flatbed 5.13 80E
1995 C3500HD DRW 6.5TD, 18' Rollback Wrecker 4.63 80E
1994 C20HD ECLWB 6.5TD 3.73 80E Wifes Truck.
1995 C20LD ECSWB 6.5TD 3.73 80E
1995 K20LD SCLWB 6.5TD 3.73 80E
1996 K30 DRW 6.5TD 4.10 80E
1997 C10 Tahoe 2Door 2WD 5.7L to 6.5 Conversion Underway