Radiator for A/C equipped 350 ?

[8door]

My 1968 C10 had the wrong engine a 350 replacement engine.
The radiator in it now has the auto trans fluid tubing , so that
confirmed the trans.
There is no SPID so have no idea re original engine size.
I added A/C and now need to get it operating, hot summer coming.
The new engine I installed is a crate 350 290 hp, the cooling is good until
hot days the temp reads between normal and hot.
The shrouded fan 5 blade, has a new hydraulic clutch.
With this setup , what would you recommend for a larger raditor to handle
the heat ?
PS this is a daily driver in sunny So.California.