Easy, swap the automatic in with the 318. Keep the 318 stock, and keep the 7 1/4 and drive it like a normal car while you save up for fun parts. Once you have it ALL, blow it apart and change the attitude.
Sorry, I don’t mean to post all this in your wanted ad. I think you are better served not spending a dime on the 7 1/4. It’s hard to find gears(above 3.23) and the sure grips are like hens teeth, expect to pay $300+ just for that. At that point it cost the same to have the rear end setup(if you can’t DIY) so you might as well only pay once.