700R4 GM in a Swinger?

And it's held up? Don't have any personal experience, but I've heard the 200r4s have had some reliability problems.

A lot of them did. The one in the '83 Hurst Olds I used to own had problems.
I'm not talking about grabbing one in a scrapyard and putting it behind your healthy small block. Like any other transmission, rebuild one with upgraded heathy internals and it will live behind big power.