Hey, you finally got in the door huh? Welcome. We make you jump through some hoops in the beginning to see if you really want in.
(not really)
As for your project, as you have seen by the comments of the other members, we not only like it, but like your motives for doing it. Great way to bond with and reach your students.
Ok, first off, every member of this forum feels that a rat rod has to be built safely and well constructed. It can have some rust, and lack of shiny stuff, but it has to be done so that it will go down the road as it should, and be constructed with generally accepted practices. The old philosophy that some rat rodders had of using things like combination wrenches for steering arms has thankfully gone away for the most part.
First thing you need to determine is what body you want to use, and the final look you desire it to be. Once you have the body, you need to make some other decisions, like what engine and transmission you will use. I also like to get the wheels and tires I am going to be using up front, and mock up the body, engine, and wheels to see what proportions and stance I like.
When that is done, you can start planning on a frame. You can modify an existing frame, like a model A Ford, or build your own from scratch. I have done both, and it is actually cheaper to build a new one from rectangular tubing. It costs about $ 100 for the tubing, and is not all rusty and weakened, like an old frame. I always build my frame from 2 x 4 lumber first, as it is similar in size to the 2 x 3 or 2 x 4 box tubing I will end up using. You can screwgun it together with sheet rock screws, and stand back and see how you like the look. If you want to change it, that is easy in wood.
Front suspension is generally early Ford type with a cross spring setup. A good way to go is a Speedway front setup (get a Speedway catalog) or use original early Ford or other brand parts. The rear axle will need to be somewhat wide if you plan on dropping an early sedan deep. My Son used a Chevy Van rear to give him clearance for his '29 Fordor (pictured below)
I'll let the others chime in and give you more ideas. Keep us posted and let us know how we can help.
Glad to see you aboard.
Don
PS: Flatbroke brought up a very good point, send the kids here too. We keep the language PG at all times, and they will be very welcome with their questions.