Thank you for the help gents. Certainly guidance right now is appreciated!

I was not sure if the yellow car was Mustang II, or Pinto? Or something else? I can't figure out if Mustang II's have radius arms. Keep in mind we never had either of those models in this part of the world, so you'll need to excuse my ignorance.

I am leaning pretty hard towards using the red chassis. Either way I am going to need to do a fair bit of work, and I'm not looking for another 5+ year project (which is what my current Torana is taking me, and I work a lot of hours on it, haha). I suspect ~400hp will keep me pretty satisfied in a Mirage. Might try and keep it a bit more simple.