Rear End Gears

When I first installed the A500 in my Duster I had 3.21 gears in an 8 1/4 with a 25.5" tire. It drove really well but to get the cruise RPM up to where I wanted it to be I was highway driving about 80 mph wherever I went. That's just where my engine wanted to be. I now have 4.10s in an 8 3/4 with 28" tires and it cruises right at about 60ish MPH. Now my combo likes about 2200 RPM cruise. Your 273 may want a little more.
I'd use the lowest (numerically highest) ratio you have available to you and try it. Only then can you really decide what you will be happy with. Once you know, save some money, sell some parts and get the gears you really want! Good luck with it! OD was a game changer for me and my car!

Cley