Hey Les - don't get too technical on me
40 rows and not sure on thickness (50mm I think).
David,
Using my Civil Enginnering brain 1 litre of water weighs 1 Kg.
Based upon a 10% increase in water capacity of my EFI Windsor (15L capacity) using an aluminium radiator the increase would be 1.5 Kg.
Guessing that an aluminium radiator would be approx 50% the weight of a cast one therefore reduced weight of an aluminium radiator far outways (no pun intended) any increase in water capacity.
Plenty of assumptions above, but I think I am on the right track