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

You CANNOT make up a driver side mount that will not require modification to the driver side mount saddle. That is because the oil pump takes up the same space. Schumacher mounts have you cut the saddle shorter and drill a new hole. Do yourself a favor and pull the k-member and modify it. The big block passenger car spool mounts are out there and often can be found on E-bay.