The 350 Chevy generates significantly more heat than a Vortec V6. The radiator's capacity, both in terms of surface area and coolant volume, is designed for the smaller engine's heat output. Using a V6 radiator on a 350 will likely lead to overheating, especially under demanding conditions like towing or in hot weather. You'll need a radiator designed for a V8, and possibly one with a higher capacity than a stock 350 radiator depending on your modifications.
