replace radiator with toyota or after market
 

Hello,
Recently, the radiator on my 97 4runner was damaged when a truck with a trailor hitch backed up into me. The repair shop plans to replace the radiator with an A/M (after market) radiator. I asked why an after market radiator and not a Toyota radiator. They said the after market is guaranteed but the Toyota is not. Does anyone know if that is true? But more importantly, does it really matter which radiator I get/use as long as it is specifically for a 4runner?
Thank you, Peter