Ebay has plenty available. I have a cheap aluminum one in my gmc. It was for a chevy so i had to notch the top for the cap but now they make them with the gmc neck too. Go figure. I use it with a LS and it cools perfectly. I wouldn’t bother using a old brass rad that not even designed to hold much more than 3-5psi. Aluminum rads are cheap and plentiful and work great.
