The photo is a '58 348/280 in a 57 4x4. I did this one in 1965, no longer have the pickup. Sorry it does not show you much about the install. I used 2 pedestal mounts in front. They may have been from the 235/6 that was in it. The left exhaust manifold touched the steering sector. I ground on it until it got so thin, I decided to grind it clear through, then welded a patch on the inside.
I currently have a 58 1 1/2 ton with a '65 409/400. I did this install in about 1970. The truck frames may be a little wider, not sure. I used the 65 exhaust manifold on the right, and a 64 409/340 exhaust manifold on the left to clear the steering sector. I used the truck horse shoe mount on the front. I could take pics of this one, but it is greasy and not much paint left after this many years of use.
Both w's replaced sixes, so bell housings/clutches had to be changed.
Ron