Given the fragile nature of the all aluminum 123 cooler I would bypass it before trying to use one in a fabricated mount. Any pressure in a place not designed for it will create a potential leak in time.

If it were me, I would try to repair it or find a proper one....if you can stand waiting for it.

A radiator shop should be able to repair it.

Tom W

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.