You don't have to graft an IFS to your frame to get disk brakes.
However, there does not appear to be a kit to install disks on straight axle trucks bigger than a half ton. This question comes up often, and no one has yet offered an easy answer.
It can be done, but you'll need to create your own conversion.
According to one guy who has done it, Dodge disks fit the existing hubs better than GM or Ford disks. If you get that far, the next challenge is making a caliper bracket.
