35” spare fits in the stock location, many people have done it... but it’s a squeeze.
I added a bit of clearance to the heat shield with a hammer, and then found it helpful to air the tire down and reinflate once hoisted and in position. Still took a bit of kicking and adjusting to get it to fit.
But Knowing that a 37 won’t fit there is why I will likely never put 37s on this truck so long as it’s also a daily driver and used for hauling stuff. Not willing to sacrifice bed space to put a spare back there and I don’t like swing out tire carriers.