Firewall on these trucks will not hold up with out some structure modification. Ugly too. This is not a recommendation, just a picture:
https://www.tuckersparts.com/Spare-Tire-Bolt-Kit.html The diaphragm is a small diameter one to fit under the floor. These come as a "kit" form lots of vendors and do fit in the space pretty well. I don't think the T-5 is wider than the SM420 but I could be wrong. Ask in the HiPo section for better help.
