I bought a Delphi aluminum/plastic 4 core replacement for my 454.
The Delphi unit is only a 2 row but otherwise is identical to my factory brass unit. The core is still the same thickness, it just uses 2 tubes instead of 4.
The aluminum radiator is about 1/3 the weight of the brass radiator.
I think Autozone, et.al has these for $130~$170.
No more brass radiators for me, thanks. The weight savings alone is reason enough to go the aluminum route.