Mobileortho narrowed his about 1-1/2 inches to bring the horizontal mounts against the frame. That's more what I have in mind when I say narrow the IFS.
The straight axle approach is what I'd prefer too. But I feel like I have a better handle on the challenges going IFS, though I may be fooling myself there.
Running the 454 I'll have to move the steering just to fit the motor. Power steering may not be necessary, but if I'm going to move the steering box, I may has well add power too.
Disk on the straight axle looks straight-forward from the other's I've seen done. Getting dually wheels under the fenders using the IFS is also managable with a little creative work.