Here is a picture showing the difference between a plate heat exchanger and a tube in shell.
This is what a OEM ford 6.0 cooler looks like. The original OEM cooler uses the plate style. That is the EGR cooler that is famous for failing.
The upgrade has the 6 tubes.
Problem is you don't use thin plate heat exchangers when you have high differential pressures and/or high differential temperatures between fluids needing to have their heat exchanged.
There is nothing wrong with thin metal plate, when used in the correct applications, they work great for oil and transmission fluid to coolant heat exchangers.
Tube in shell are used in boilers. High delta pressure, high delta temp.
An EGR cooler used in a diesel EGR cooler application sees both high temperature and pressure differentials. A repurposed EGR cooler will see the high temperature differential but on the pressure side there wont be nearly as much.
