700R4 GM in a Swinger?

Phoenix is very reputable. In fact, Greg (the owner) runs a 4L60E behind a potent sb stroker in his e body. Granted, the 700R4 is a less evolved version, and not electronic, but basically the same thing. One of these units is a good idea as they can be built to take up to 500+hp as offered by many good builders out there. The big bonus is that this unit has the mount within a 1/4" of where the torqueflite is. The 700 has a bad rap from the early years, but is a good unit if built right.
I have seen some 518 installations that have been downright brutal. If I were going this route, and have thought about it, I would go for the 700. Spend the money for a trans that has good parts, good converter as well. Also, go for a nice (aluminum ) driveshaft to keep up with the higher driveshaft speed of OD units and have fun.