Right now i have a 97 F350 Single cab 460 truck. Its got 4" lift and 35x12.50's on it. I need new tires, im debating on keeping it how it is and just getting new tires or going to 37's. I plan on doing shackle reversal up front 3" and then leaves out back to make it sit level. My question is if i do the shackle reversal, can i fit a 37x13.50 tire or can i only go 12.50. Its on a 16" rim.