I've got an original V8 and an original 4BD1 radiator, and the only difference I can tell is that the inlet and outlet are swapped around. The V8 rad has a bent top tube (inlet) and the 4BD1 has a bent bottom tube (outlet).
Both are the same otherwise (no of cores, dimensions etc).
I also have a V8 rad from Gary (CLR) and the biggest difference between this one and the original is that the original has staggered cores Vs the aftermarket, which has in-line cores (couple of pics of buggered staggered core radiator here). I can take some more pics tonight if you're interested (4BD1 Vs aftermarket V8) - the other V8 radiator is currently residing at isuzurover's place.
The fins on the original also protrude several mm past the cores which I think might protect them from light hits, while the fins on the aftermarket are flush with the core & quite exposed.
Cheers
Bojan
