May not necessarily be a dead end. It all depends on the construction. Look at 2000-01 Dodge and Ford F450-550 front brakes. A hat (rotor) with a wheel hub extension attached to get the "duelly" wheel further out.
Let's look at a 1989 P30. From inside backing plate to inside backing plate is 65". Spring center to spring center is 35". From center of kingpin tube to top of spring pad is approx. 5". Now, like I mentioned the possibility earlier, the wheel mount is 10 lug with a 8R19.5 wheel / tire attached. However, here is where we get to that construction thing. Looking in the wheel, you'll see that there is a wheel extension. Held on by 8 bolts or studs. From the backside of the backing plate to the face of that 8 bolt area is approx. 4" From the 8 bolt area to where the wheel mounts is another approx. 5". This is to get that duelly wheel out there. This is a duelly / "I" beam front end.
Yep, couldn't get to that 3/4 ton Dodge. But I was able to crawl under the P30 and measure it a little.
