i was just looking at bill's site and noticed the tests he did on the heater cores.
In the rig that i will test the block i have the ehiem 1048 pump and a big momma style heater core with 2 12cm fans in push and pull config.
this is before i put the shroud and second fan on and also changed the rig to pump > cpu > rad to make sure the jet get's as much pressure as possible