The V8 in the MGB was known to run warm and similar techniques were used. My first choice would be a radiator with a greater surface area. The limitations with this is that its hard to go wider due to space, but it's possible to go a bit higher, and a greater increase at the bottom. But all of this extra area isn't exposed to airflow, so the gains won't be proportional. A thicker matrix is choice number 2, but again, thicker won't give a proportional improvement because the additional thickness will get slower, pre-warmed air. Probably the greatest benefit from both these upgrades is the additional volume of coolant. By the same token a larger heater matrix, if possible, will also add volume.


DaveW
'05 Red Roadster S1
'16 Yellow (Not the only) Narrow AR GDI Plus 4