Looking to fabricate my own engine mounts,have some questions.

Yeah this would be option two for me is modify the K frame,may have to go this route but preferably just fabricate the mounts that go on the block itself.
It is much easier to modify the K frame to work with factory mounts than it is to build custom mounts. Watch the video a couple of times and then take a look at your K frame. If you don't have the tools or talent to do it yourself you should be able to find a local shop who can handle it. It is very basic street rod fab. Cut, move, reinforce, weld.