At an impasse with rear wheel/tire fitment

Installing longer studs would be a 10 minute job, especially if the axle is for temp use only.
Knock back the orig. studs with a hammer, either or not with a piece of wood in between to save them for later use and pull in the new studs with some spare wheelnuts.

You could also try loosening the rearaxle U-bolts slightly with the car supported and see if you can pry/move the axle on the leafsprings a bit to gain just the clearance you need.