Heater core

[GN ARCH]

I ripped out the heater core in my car today and I bought one for the car years ago I knew it was going cause it use to smell in the winter when I drove the car sometimes but last year I saw a puddle on the right side carpet and haven't driven the car since today when I brought it home to replace it and realized that they have given me the wrong heater core my question is where can I get an ac delco heater core or something compatible that's good quality cause I hate to do the job twice cause of a shitty Chinese heater core