Most radiator shops won't attempt to fix them as they are hard to clean and they cannot get to the inner areas to make a repair. Before you give up on it get the engine up to operating temperature and put about a 1/4 of a can of ground black pepper in the radiator. Take it out and drive around. You would be amazed how well it works.
Fred


1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine