Is it possible to swap a 4g63 into a factory 420a car? Yes. Is it generally feasible? No.
Transmission is on the opposite side, motor mounts are completely different. Wiring harness is completely different.
It is relatively easy to boost a stock 420a, provided you stick with a low-boost application. If you were to use a 16g, you wouldn't want any more than 8PSI, or you risk serious engine damage. Now, if you're willing to drop $1500 on forged internals, and Megasquirt; The engine should be able to handle anything you can throw at it.
Now, if you are hell-bent on an engine swap, you may wish to look into a 2.4L from one of the cloud cars "Stratus, Cirrus, etc..." Some SRT components can be used to make it "boost ready/friendly."
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