Everytime my rad has developed a leak(twice in 22 years) it has been between the side tanks and rad core and nobody wants to attempt to repair it because they never seal correctly.
The only aftermarket rad that was available was a Valeo who was also the OE manufacturer for Chrysler.
My local rad shop whom we dealt with at work for 20 years did some detective work for me when I needed one a few years back and found one in a shop in upstate N.Y.
He did tell me that rad was the only one he was able to locate.
He had to pull out an old paper Valeo catalog just to find the part # because it is no longer listed.
The VNT rad has been long discontinued by Mopar.