Front suspension issue

Okay so I bought the PST front end for the 68 dart with single piston calipers. I was told this kit would work fine for my car. The reason being is that the car was originally equipped with drums and a 6 cylinder, and now has the 11" discs, single piston calipers, with a 318, it was out of a donor car, not sure which one, from what was guessed on the forum possibly a 73 duster.

The kit doesn't come with inner tie rod ends and I bought some for a 68 dart from oreillys for about $80. I then checked for 73 duster ones and they were like 13 bucks! The pitman arm and idler arm seem to be cheaper too!

Will these parts work on my car? Also why are they cheaper?