Does any know where I can find out if a swar bar on a 93 sentra would fit a 91 corolla?

Call a sway bar manufacturer like Hotchkiss, Herb Adams, APC...

My guess is absolutely not. The chances that a Nissan bar would fit a Toyota are no better than one from a 64 chevy.

Well, both cars are early 90's. Both have the same size engine and body style. Same set up under the hood so I started wondering if the sway bar on one would fit the other, but maybe I'm wrong.

Well, both cars are early 90's. Both have the same size engine and body style. Same set up under the hood so I started wondering if the sway bar on one would fit the other, but maybe I'm wrong.

To a certain extent your thoughts a following the right track.
There are plenty of cars from different manufacturers where some parts can be inter-changed.
A ford 9 inch diff for example can be adapted to fit almost any live axle set up. Its not a bolt in swap, but it can be done.

Of course car design has come rather a long way since the 50s and 60s.

Now days there are so many different ways of designing a car, that all the manufacturers use very different designs for all their parts.
So inter changing them is almost impossible, even on simple things like sway bars.

You get a bar made for not much more than it costs to buy one.