Bolt your trans in place with stock mount, remove motor mounts, and hang engine in place with an engine hoist and move it around till the headers clear. Then try and find a motor mount/shim combo that will work in the given location.
Bingo. the trans mount seems to be the only constant you can get a good reference for the rest of the motor, thats how I made custom mounts for a motor, hung it llevel and bolted up the trans mount and started cutting a styrofoam block to the dimensions where it would wedge in where the original brackets would go. Worked pretty good, just make a metal box the shape of the styrofoam. Shims are where its at!
