There were six axles offered by Ford for these cars.
There was the standard 3:1, and 2 other ratios. Then all 3 were available in limited slip form.
At least 95% of these cars had the 3:1 gears.
I had my "pumpkin" rebuilt a few years ago, and at the time was tempted to try another speed, but finally decided to go with what was stock. For what it's worth, both axles were slightly bent, and just recently I had new ones made by Moser, and new springs -- HUGE improvement in ride and handling!
If you have the slightest doubt about the axles themselves, I recommend investing in new ones -- and bearings, seals, etc. As for the pumpkin, it's simply a matter of choosing which gears you want and swapping them out. Get new ones -- chances are there's a place locally that specializes in such gears and you can pick them up. If you're taking the car to a shop, moist likely he knows where to go. The only OTHER consideration is the gear in the transmission -- you can get these at Mac's or elsewhere. You need this to keep your speedometer correct.