My comments refer to XJS and Ser III V12 radiators but I'm reasonably sure all are the same in principle....

The V12 radiator has two upper hose connections and the core itself is partially segregated by an internal baffle. In essence, it's almost like two radiators in one, with coolant finally being blended together at the bottom where there's a conventional single hose.

A radiator shop could modify the radiator or you could fabricate some sort of "Y" arrangement for the upper hoses.

I'm not sure if it's worth the effort and expense. The radiators were barely adequate for 5.3 litres of V12. Not sure one would do much better on 5.0 litres of V8.

I'd try to find an aluminum radiator.

Not sure what's available to you but some guys in the 'States have been using aluminum radiators from Mustang V8s, circa 1997-2004.

Cheers
DD