I'd suspect crankcase contamination from leaking coolant would be why the heat exchanger was discontinued, it's almost surely better in every way cooling and heating wise (As an engine that gets up to temp faster is more efficient and better lubricated, sometimes just as important as cooling a hot one).

__________________
Current:
2021 Charger Scat Pack Widebody "Sinabee"
2018 Durango R/T

Previous:
1972 280SE 4.5
2014 Jeep Grand Cherokee Limited "Hefe", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi"
1999 Chrysler 300M - RIP @ 221k