The Mustang 5.0 got forged or hypereutectic pistons versus cast slugs in the truck but the compression ratio is the same, and it got a larger roller cam but otherwise the longblocks are identical.. same block, heads, crank, and rods. The Mustang also got a special intake manifold but it's actually quite a bit smaller than the truck version so I would not suggest bolting one on unless you're gonna leave the rest of the motor completely stock and just want a small boost in low rpm torque.
There's not enough difference between the 95's roller cam and the Mustang's roller to exactly qualify it as being larger. The easiest way to gain 15 hp is to just replace the stamped steel rockers with a set of 1.7 full roller rockers, this will bump the lift specs up to match (actually best the Stang's exhaust lift) the lift between the two grinds. The lift specs are .422/.445 for the truck cam, vs .445/.445 for the HO, going to 1.7 rockers moves the lift of the truck cam to .445/.473. As far as the duration figures, that depends on where you source the specs from. One source lists the HO as 276/266, one says 276/276. the truck cam is 256/266