what is a K frame

That is the main sub frame in the front of the car that goes between the front frame rails and holds the engine and front suspension.

The k-frame engine mounts are usually different from slant 6 to v-8. You would have to either change the k frame to a v-8 one, or get a set of shumacher slant 6 to v-8 conversion engine mounts. If he doesn't have an extra k-frame to throw in on the deal, it is up to you....

The dash boards can be removed. You have to take out the windshield to get to the screws at the front of the dash frame. then there should be a "blank" panel that goes where the push button trans controls were if you have a floor mounted manual trans. You would have to find a dash from a manual trans car, or at least get the bezel for that section for yours.