I just put 37 KM3's on my truck and then looked at putting a full size spare underneath. I read lots of threads on what should/does/doesn't fit etc. but wanted to post some pics of my experience. I have a spare 37x12.5 KM3 but also a spare 37x12.5 K02.
The fit is tight to say the least. The tire has 20psi in it for reference as well. I cranked her up and then ratchet strapped it to the hitch to bring it closer to the hitch and furthest away from the diff possible (swings back on compression a bit). I am running aftermarket exhaust but stock pipes from the axle back. I loosened them at the rear bumper/hitch mount and moved them as far outwards (left and right) as possible to try and clear the tire with at least an air gap. I have heatshield contact in 2 spots but it's minimal and I am not concerned about the heat rejection from the exhaust at that point damaging or negatively impacting the tire. Tailpipe temps usually are 3-500 deg F, rubber vulcanizes usually around 300-350 but I'm not in direct contact on a large surface area of the exhaust. I guess we'll see..
Also some pics of a stock tire, 37 km3 and 37 k02.
On the Km3 I am running the beadlock conversion so the outer bead was moved to the outside lip of the tire likely explaining why it looks a little flatter and wider than the K02. They are indeed the same size tire.
The fit is tight to say the least. The tire has 20psi in it for reference as well. I cranked her up and then ratchet strapped it to the hitch to bring it closer to the hitch and furthest away from the diff possible (swings back on compression a bit). I am running aftermarket exhaust but stock pipes from the axle back. I loosened them at the rear bumper/hitch mount and moved them as far outwards (left and right) as possible to try and clear the tire with at least an air gap. I have heatshield contact in 2 spots but it's minimal and I am not concerned about the heat rejection from the exhaust at that point damaging or negatively impacting the tire. Tailpipe temps usually are 3-500 deg F, rubber vulcanizes usually around 300-350 but I'm not in direct contact on a large surface area of the exhaust. I guess we'll see..
Also some pics of a stock tire, 37 km3 and 37 k02.
On the Km3 I am running the beadlock conversion so the outer bead was moved to the outside lip of the tire likely explaining why it looks a little flatter and wider than the K02. They are indeed the same size tire.
