Radiator upgrade Needed

[OldSparky]

I have a 1964 GMC pickup with the 230 cu engine. It had been parked in a field for over 35 years. After replacing the coil, points, and condenser I was able to get the engine to run by filling the carb bowl with gas. I started adding water to the radiator so we could run the engine longer than just a minute or two safely, but the radiator has too many holes to repair. I would like to upgrade the engine later (probably much later) with an LS. Rather than get an exact replacement radiator now, and then have to buy another radiator later, I would like to know what size radiator (make/model of substitute) could be made to fit. Thanks.