radiator transmission lines help

? Explain

Too many parts in these older cars have rigid mountings. Stress and vibration cracks stuff. Then your engine and trans can move. See where I'm going here ?
Newer cars can get by with plastic radiator tanks but.. those lines have rubber hose sections and the radiator is mounted in rubber saddles.
I would be afraid to use the trans cooler built in a aftermarket radiater too unless I put a rubber line section near the radiater. That still isn't as fail safe as a external aftermarket cooler.